Assalamu alaikum students, I am Wasimi Kram. This is the fifth lecture in a series of 45 lectures on digital logic design. How are you today? I hope you have been keeping well. But before that, let us have a look at the material which we covered in the last lecture. In the last lecture, we looked at the octal number system, which is in fact a base 8 number system. It gives you 8 different values. We said when you write long strings of binary numbers, then you could generate an error. So to represent long strings of binary numbers, you use the octal representation. While the hexadecimal number system is present, the octal number system is not frequently used. But still, since we are studying different number systems, so octal is again an important number system. We talked about converting from binary to octal, octal to binary, then octal to decimal, decimal to octal. Standard methods are used, divide by 8, sum of 8 methods are used. Next, we talked about alternate representations. First, we did 4 representations, twos complement, unsigned, unsigned, magnitude, floating point. In addition, there are some representations which are being used in special applications. We talked about the access code. Where is the main use of the access code? We used it in the floating point representation. We also talked about the BCD code. BCD code we said was the binary coded decimal. When we need to display decimal numbers or write decimal numbers, we generate a binary code to represent those decimal digits 0 to 9. So, we have to use a 4-bit binary code which has 10 different values to represent numbers 0 to 9 of course. Gray code we said is not a positional code. Gray code we said is not a positional based code. The important thing about gray code is that when you count, let us say 4, 3, 4, 5, successive numbers, the number of bits that change is limited to 1. We saw an application of that. You have a motor, a rotating machine. You have to know at what angle it is. So, you attach a disk to it through gray code. So, when the machine rotates, you would get to see different numbers and those numbers would represent the actual position in terms of angles. We also talked about alpha numerical codes. Alpha numerical code is because when you write a text, you have characters in it. A, B, C, D, small A, B, C, D, punctuation marks, numbers are also there. Even though we have discussed all the codes, they all deal with positive, negative numbers, fractions and of course, integers. So, ASCII code is a 7-bit code which gives you up to 128 unique symbols. Every symbol has a binary 7-bit representation which you are storing in a digital system and using it. We talked about an extended version of the ASCII code which is an 8-bit ASCII code. 8-bit ASCII code allows you up to 256 different characters or unique codes. If you want unique characters, then you have another code, the unique code. This means 16-bit representation here. So, you can represent up to 64,000 characters. The last two topics which we discussed was the detection of errors using the parity bit. So, we said one way of detecting an error is to use the odd parity. The other way is to use the even parity. So, both the methods are very similar. When you detect an error, you cannot correct it. That is another subject. Up till now, we have been talking about numbers or characters which we represent in terms of binary digits or bets. Now, the important question is, how do we process all this information? The digital systems which need this information, how do we use it? Well, in the first lecture, we mentioned that digital systems are based on basically digital circuits and the building block is the logic gate. So, logic gate is the most important component or the smallest component which can be combined with other logic gates to form a digital circuit. So, today we would be talking about logic gates. Now, before we move on and discuss about logic gates, let us discuss an example. A motorcycle. Before using a motorcycle, you should know about it. For example, how many liters of fuel does it require? What is its maximum speed? How frequently should you service the motorcycle? How many, how much load can it carry? There are three or two motorcycles in it. Now, if you meet or fulfill all the specifications, then of course, you would be able to use the motorcycle for a longer duration of time. If you are misusing it, it will get spoiled quickly. Now, in electronic terms, each component which you use in an electric circuit has its specifications and characteristics. So, each component has to be used based on those characteristics. For example, you have a transistor. There are three pins in it. So, before you can use the transistor, you should know what it does. You should also know what are the input voltages and what are the output voltages? Another important criteria is its gain. What is the output voltage? Frequency response. There are different characteristics which you have to study. Now, when you implement an electric circuit, how would you describe it to somebody?   When you make a house, the architect will first make a whole map. He will indicate where the doors are, where the windows are, where the room is, where the kitchen is. Similarly, when you implement a digital circuit, you have to draw a circuit diagram. What would be the circuit diagram? Connections. Which components are connected to which? The components themselves. For example, if you are using a transistor, which transistor? How would you describe a transistor in a circuit diagram? It has a unique symbol. What is its symbol? It's a zigzag line. What is the capacitor? You can see two horizontal lines. So, these are the symbols of these components. Now, let's turn back to logic gates. Logic gates, we said, are the basic components or the basic building blocks of a digital circuit or a digital system. Now, when you design a digital system and implement it, you need to have its circuit diagram. In the circuit diagram, what do you see? You would be seeing all those gates which are connected to each other. So, each gate would be uniquely represented by a symbol. Now, when you connect all these gates, you also need to know how these gates function. What are their characteristics? So, today we would be looking at all these gates which are used in digital logic design or digital circuits. And the issues which we would be looking at would, of course, be the symbols. We would describe a gate and a gate. What are the symbols? What else? What is the other important information which you need to know about a gate? How does it work? What is its function? What are its inputs and outputs? Now, you have to tell someone about a gate. So, how would you convey that information? Well, one way is to draw out a table. In the table, you will write the inputs and the corresponding output values. So, one way of describing the function of a logic gate is through a truth table or a function table where you list all the inputs and the corresponding output values. Another way of describing the function of a logic gate would be by writing a mathematical expression or a formula. So, two ways of describing the function of a logic gate. The other important issue which we need to know about a logic gate is its performance for a certain period of time. Now, when you connect a logic gate in a circuit diagram, you would be continuously applying signals to its input. So, for example, let us suppose an AND gate which is used for 10 seconds. For 10 seconds, you would be wearing the inputs. So, of course, for the 10 second time period, you would be getting either different outputs or the same outputs. So, you need to convey that information as well. So, how would you convey that information that how a gate works during that 10 second interval through a timing diagram? So, when we describe an AND gate or any other gate, we would be describing or we would be identifying the gate through its symbol. We would be describing its function through a truth table or a function table. We can also write an expression which represents the operation or the function of the gate. And we would also be describing or writing out its timing diagram. So, now let us look at the different gates which are used in digital logic circuits. Basically, there are three gates which are used, the AND gate, the OR gate and the inverter. Let us start by looking at the AND gate.  You will see the exact diagram of the symbol which represents the AND gate. An AND gate can have a number of inputs, but it has to be more than one. So, it could be a two-input AND gate, three-input, four-input, multiple-inputs can be there. And a AND gate always has a single output. So, if you see the symbol of a two-input AND gate, you would see two lines which represent the two inputs and one line at the other end or towards the curved end of the U which indicates the output of the AND gate. So, this is the symbol. If it is a three-input AND gate, you would see three lines at the input indicating the three different inputs. So, multiple input AND gates would have multiple lines at the input AND. Now, how would you describe the operation of this AND gate? We said we would be using a truth table or a function table. Let us consider the example of a two-input AND gate. So, look, you could apply both zeros at both inputs or a combination of zero and one or one zero or one one. So, four possible combinations are applied at the input of a two-input AND gate. What is the output for each of these four combinations? If there is zero-zero input, the output is zero. If there is zero-one input, the output is again zero. If there is one-zero input, the output is again zero. Only for the inputs one-one, the output is one. What is the function that is being implemented? If you remember, when we talked about binary multiplication, this is exactly what was happening in binary multiplication. When we multiplied two single binary bits, then when both the bits were ones, only then the answer was a one. For all other combinations, the answer was zero. So, if you say that you implement multiplication for binary numbers, you can use an AND gate. It implements the multiply function. Now, how would you represent the operation or the function of this AND gate in terms of an equation? Well, let us consider that f indicates the output of the AND gate and a input a and b indicates the two inputs of the AND gate. So, the equation would be or the function representing the operation of the AND gate would be f equals to a dot b. The dot is the AND operator. Now, if the AND gate is a multiple input AND gate, let us suppose four inputs a, b, c and d. So, how would you write its expression? It would be f equals to a dot b dot c dot d. What would be the function table of the AND gate? Well, it would have four inputs or four input columns a, b, c, d and a single output column f. How many possible combinations are there? Remember, four-bit input. So, if you use a four-bit input binary number, you can get 16 different combinations. So, in 16 different input combinations, what would be the 16 different outputs? Well, for all cases except for the case where the inputs are all ones, the output would be zero. So, once again, if your input is all ones, the output would be one. For all other cases, the output would be zero. So, this satisfies the function, the expression which we had written or multiply function which satisfies that as well. Now, let us look at the timing diagram. Let us suppose you connect this two input AND gate and you apply different inputs for, let us say, a time period of 10 seconds. Inputs vary, enhancement. So, what do you get at the output? You would get 10 different outputs or perhaps the same output. It depends on the input values. So, let us have a look at a slide which shows the timing diagram of an AND gate. The combination of ones and zeros applied at the A input of the AND gate is represented by the timing diagram, the timing shape A. The combination of zeros and ones applied at the B input of the AND gate is shown by the wave shape B. Now, both these inputs vary over a time period of seven time intervals, T0 to T6. Now, let us have a look at the output. Now, in the time interval T0, the input A and B both are logic one. So, what is the output? Well, considering the function table, the output has to be A1. Consider the time interval T1. The input A is zero. The input B is one. So, what should be the output? It should be zero. Similarly, at time interval T2, the input A is one. The input B is zero. The output is again zero. At time interval T3, both the inputs A and B are logic one. The output should be one as seen in the timing diagram F. At intervals T4, T5 and T6, the output is zero because the inputs have a zero value. The timing diagram which we saw describes the operation of the AND gate for seven time intervals. Well, we can extend this time interval to let us say 100 time intervals or 200 time intervals. The thing which I forgot to tell you, there is an alternate symbol which represents the AND gate. It is a square with one pin at the output which indicates the output and two lines at the input side. Within the square you have an ampersand symbol which basically indicates an AND gate. Now, let us look at the OR gate. The OR gate is represented by a symbol which is similar to a V lying on its side. The V is a closed V, of course. The corner of the V has the output of the OR gate and the other end, the closed end of the V has the inputs. So, like the AND gate, OR gate can be a multiple input OR gate. Of course, inputs have to be more than one. So, the minimum number of inputs have to be two, maximum 10B or 12B. Normally, you have three inputs, OR gate, four inputs, five, six. Now, how does an OR gate function or rather what is the function of an OR gate? Now, that can be described by looking at the function table or the truth table of an OR gate. Let us consider the two input OR gate. Now, how many inputs? Of course, two inputs. So, input A and input B. How many outputs? Of course, OR gates have a single output. So, the output is output F. How many input combinations can we apply to a two input OR gate? Again, it is two raised to power two. So, four different input combinations. What are those input combinations? Well, 00, 01, 10 and 11. Output, what is it? Well, for the combination 00, the output is 0. For the combination 01, the output is A1. For the input combination 10, the output is again A1. For the input combination 11, the output is again 1. So, OR gate's case may, when input, both inputs are 0, only then the output is 0. For all other cases, the output is 1. If you compare this, and if you recall, the binary addition that we did, what was it? Very similar. When we added 1 and 1, we had a sum part which was 0 and a carry part. If you look at the OR gate operation, the OR gate operation is different. It is different from the rest. So, OR gate operation is described as a Boolean addition. Now, what happens if we have a 3-input or a 4-input OR gate? How will that behave? Well, let us consider the example of a 4-input OR gate. So, there will be 4 inputs, A, B, C and D. Output, of course, will be F. Again, how many input combinations can be made? Well, there are 4 bits, 4 inputs. So, 16 different combinations can be made. 2 raised to the power of 4, 16. Now, one output will come for which combinations? Well, if you look at the function table or the truth table for the 2-input OR gate, you would see that, again, if all the 4 inputs are all 0s, only then the output would be 0. For all other combinations, of course, the output would be A1. This OR gate function, one way or the other, we have told you that you are describing the truth table or function table. How will this be written in the expression form? Well, let us again consider the example of the 2-input OR gate. So, the expression would be F equals to A plus B. So, the plus operator indicates the OR operation. This is not the add symbol. The plus sign here indicates the OR operation. The OR gate asset was represented by a closed V lying on its side. An alternate symbolic representation of an OR gate is a square with one line at one end representing the output and some more lines on the other end representing the input. Within the square, you have an equal to greater than sign which represents the OR gate. Now, we would be interested in the timing diagram of an OR gate. That is, if a certain set of inputs, continuous inputs are applied at the input of an OR gate, what would be its output? How would it behave? So, let us have a look at the timing diagram of an OR gate. Let us consider a 2-input OR gate and having inputs A and B. The combination of 1s and 0s is applied at the input A and again another combination of 1s and 0s is applied at the input B. The timing diagram shows both the inputs A and B. The output remains high for the entire time interval that is from T0 to T6. Let us see why. Well, considering the time interval T0, the input is high, logic 1. The input B is high or logic 1. Now, referring to the function table or the truth table for the OR gate, the output should be A1. Considering the time interval T1, the input A is a 0, the input B is a 1. So, what should be the output? If any input is 1, the output has to be A1. Similarly, for time interval T2, the input A is a 1, the input B is a 0. So, what is the output? It should be again 1. If any input is A1, the output has to be A1. Similarly, if you look at intervals T3, T4, T5 and T6, and these 4 intervals, either both the inputs are logic 1 or only a single input is logic 1. For all these 4 cases, the output has to be A1. We just looked at the timing diagram of a 2-input OR gate and we observed the inputs and the outputs for time interval of 7, T0, say like a T6 that. OR gate code OR kinkathane. Well, the English word OR means this or this. So, if you look at the function table, if any input is 1, the output is 1. So, this OR this is A1. This is the AND gate code AND kinkathane. Again, it is the English word AND. That means this AND this should give you the output. So, if both the inputs are 1s, only then you would have the output 1. If any of the inputs is a 0, then of course, the output is not going to be A1. Let us look at the third gate, the inverter gate. The inverter gate is also known as a NOT gate. Symbolically, it is a triangle with a line leading end to the triangle and another line coming out of the corner of the triangle. At the corner or the pointed end of the triangle, you have a bubble, a circle. This symbol represents what? Well, the input applied at the NOT gate is inverted at the output. Now, as you can see from the symbol, a NOT gate has a single input and a single output. This is the only gate which has a single input. The output is of course 1. Let us have a look at the complete function of a NOT gate. So, the function table would have an input column A and output column F. How many combinations can we apply at the input? Since we only have a single input, so you could only apply either a 0 or a binary 1. So, if you apply a 0 at the input of a NOT gate or an inverter gate, what do you get at the output? Basically, 0 is inverted at the output. So, you would get a 1. Now, if you apply a 1 at the input, what do you get at the output? Again, it is inverted. So, you would get a 0 at the output. How will we write this function in the form of an expression? Well, if F is the output, so the expression representing the operation of a NOT gate would be F equals to A bar, A cube per bar. So, in digital logic, whenever you see a bar on top of a letter, that means that particular variable has been inverted. So, A is an input variable. So, bar means, it has been inverted and that is equal to the output F. Now, can you have a multiple input NOT gate? Well, we said no. Inverter or NOT gate ka kaam yeh hai ke ek hi input ko leke invert ka rahe usne. So, it is not possible to have multiple inputs. Output to hota hi ek hai. Now, let us have a look at the timing diagram of an inverter. How would it behave when we apply a set of 0s and 1s at the input of a NOT gate? Since the inverter or the NOT gate has only a single input, so you can only apply a sequence of 0s and 1s at the input A, which is shown in the diagram. The inverter or the NOT gate has a single output, so the output is shown by the timing diagram represented by F. Let us discuss the inputs and outputs during different intervals. At T 0, the input is 1. Since the NOT gate inverts the input, so what should be the output? It should be 0. Similarly, at interval T 1, the input is 0. So, the output should be inverse of this, so it is A 1. Similarly, during intervals T 2 and T 3, the input remains A 1. The output has to be a 0. And similarly for intervals T 4, T 5 and T 6, you can see that the output has been inverted. We have just looked at the timing diagram of a NOT gate. Before we move on any further, let us have a look at the use of these 3 gates, the AND gate, the OR gate and the NOT gate. So, let us have a look at the diagrams. The AND gate can be used to enable or disable a device. Consider a counter. How does a counter count? Well, it is connected to a clock input. So, as the counter receives the clock pulses, it increments its count. So, perhaps it is at the number 1, it receives a clock pulse, it increments to 2, it receives another clock pulse, it increments to number 3 and so on. Now, you can disable the counter by stopping the clock pulse from reaching the counter input. So, how do you do that? You connect an AND gate to the input of the clock input of the counter. Now, the AND gate has the input A and another input B. The clock is connected to input A of the AND gate. And the input B is connected to a switch. If the switch is set to 1, the AND gate would allow the clock pulses to be available at its output. So, the counter would start counting. If the input of AND gate B is disabled or set to 0, what would be the output of the AND gate? It would be 0. So, no matter what the clock is, it is high or low, the output would remain as 0. So, in fact, by setting the input B of the AND gate to 0, you have disabled the output. The output remains as 0 and the counter does not count. Now, let us consider the application of an OR gate. A car has 4 doors. So, an OR gate can be used to sound an alarm if any of the 4 doors is open. Let us have a circuit which generates 5 volts when any door is open. So, let us suppose all the doors are closed. So, the 4 circuits would be generating a 0. If all the outputs of these 4 circuits are connected to the 4 inputs of an OR gate, what would be the output? It would be a 0. Let us suppose the front left door is open. The circuit would generate 5 volts. Now, this is considered to be a logic 1. So, what are the inputs to the OR gate? Well, the 3 inputs would be 0. The single input which is connected to the circuit of the front left door would be 1. What is the output? It is a 1. Now, the output of the OR gate is connected to an alarm. So now, whenever any of the 4 doors or all 4 doors are open, the inputs would be 1s corresponding to the open door. The output would of course be 1 and the alarm would be sounded. Let us consider the application of NOT gate. We talked about calculating the 2s complement of a number. So, how do you calculate the 2s complement? Well, you first calculate the 1s complement. How do you calculate the 1s complement?  So, if the number is 1 1 0 0 1 0 1 0, its 1 complement would be 0 0 1 1 0 1 0 1. So, how do you perform this 1s complement? By using NOT gates. So, how many NOT gates do you require? Since the number is an 8 bit number, so you would require 8 NOT gates. We have just looked at applications of the AND gate, the OR gate and the NOT gate. Now, before we move on, let us look at alternate representations of the AND gate and the OR gate. Symbolically, the AND gate is represented by a closed U lying on its side. The AND gate symbol can also be represented by the OR gate, the closed V symbol. But the inputs have bubbles and the output also has a bubble. So, the general rule is if you need to represent a gate by its alternate symbol, you just select the other symbol. If the AND gate symbol is there, you select the OR gate symbol. The other thing which you need to do is to put bubbles at the inputs and the outputs where there are no inputs. So, if you consider the original AND gate symbol, it does not have bubbles at the inputs or the outputs. So, when you select the alternate symbol, which is the closed V, you would put bubbles at the inputs and the outputs. If we define this symbol, what does it represent? The OR gate symbol indicates this or this. Since a two input AND gate has two bubbles at the inputs, that means zero or zero, what should be the output? The output again has a bubble. So, the output is zero. So, this means this zero or this zero would give you a zero at the output. Now, if you look at the function table of an AND gate, what do you get at the output? Well, if any of the inputs is a zero, the output is a zero. So, this alternate symbol is exactly explaining the same thing. Let us look at the OR gate symbol. The OR gate symbol is of course the closed V lying on its side. The OR gate symbol which represents the OR gate is the AND symbol. The inputs and outputs at the inputs, you put a bubble at the outputs. What does the bubble mean? It means invert. So, let us see what this alternate symbol for an OR gate represents. It means zero AND zero should give you a zero output. Now, if you just remember or you look at the function diagram or the two table of the OR gate, when does one come? If any of the inputs or all inputs are a one. If both inputs are a zero, what do you get? The output is a zero. So, this is what the second symbol represents. We have just looked at the alternate symbolic representations of the AND gate and the OR gate. In the handouts, I have given some examples. So, that would help explain the alternate representations of the AND gate and the OR gate. By the way, the inverter gate can be alternately represented by a bubble not at its output but at the input. So, inverter be doh tarikon se aap represent ka sakte symbolically. Now, let us go back to the gates. We have talked about AND gate OR gate and NOT gate. Let us continue our discussion with the NAND gate. NAND gate basically, again, it has multiple inputs and a single output. The number of inputs has to be more than one and of course, it can be more than 10-12. What does the NAND gate do? Basically, it is a combination of the AND gate and a NOT gate. So, if you connect a NOT gate at the output of an AND gate, that would give you a NAND gate. Let us look at the function table or the truth table of a NAND gate. Let us consider the two input NAND gate. What are the inputs A and B? What is the output F? Again, it is a two input NAND gate. So, you have four different combinations 0 0 0 1 1 0 and 1 1. What is the output? Well, for 0 0, the output is A 1. For the combination 0 1, what is the output? Again, it is 1. For the combination 1 0, what is the output? Again, it is A 1. For the input combination 1 1, what is the output? It is A 0. Now, if you compare the output of a NAND gate with that of an AND gate, you would see a direct inversion between the two outputs. So, that is what we explained earlier. NAND gate is made up of an AND gate along with a NOT gate connected to its output. Let us have a look at a mathematical expression which describes the function of a NAND gate. Well, we are using a two input NAND gate. So, it has inputs A and B. So, the expression would be F equals to A dot B and bar over the entire expression. Bar, we said, represents the inversion. So, in fact, the product of A and B is being inverted. Simple what will happen of NAND gate? Well, it is very similar to that of the AND gate with a bubble at the output which indicates that the output is being inverted. Let us have a look at the timing diagram of NAND gate. Again, we apply a certain number of inputs, rather a train of binary numbers at the inputs and we observe the output. And we simply draw a timing diagram which explains the behavior during that particular time interval. Let us consider the example of a two input NAND gate. We apply a series of 1s and 0s at both the inputs A and B which are shown in the diagram. The output F is again shown in the diagram. Let us consider the time interval T0. At time interval T0, both the inputs are a 1. What should be the output? Referring to the truth table of the NAND gate, the output should be 0. Whenever all the inputs are 1s, the output is 0. Consider the time interval T1. The input B is a 1, whereas input A is a 0. So, what should be the output? Referring to the function table or the truth table of the NAND gate, if any one of the inputs is a 0, the output is going to be a 1. So, during time interval T1, you see a 1 at the output. Similar is the case with time interval T2. Input B is a 0. So, the output has to be a 1. Looking at interval T3, both the inputs are 1s. So, the output has to be a 0. Intervals T4, T5 and T6, you see an output which is high or 1. Why? Because during intervals T4, T5 and T6, one of the inputs is a 0. We have just looked at the timing diagram of a 2 input NAND gate. Before we move on and talk about the universal NAND gate, let us talk about a 3 input or a 4 input NAND gate. Do we have a 3 input, 4 input NAND gate? Yes, NAND gate can have multiple inputs more than 2 inputs like the NAND gate and the OR gate. Function table, let us say a 4 input NAND gate. Again, the same NAND gate case or OR gate case method. You have inputs A, B, C and D. You have 16 possible combinations. So, you have 16 possible outputs. So, 4 input NAND gate output, what will happen? Well, again, if all the 4 inputs are 1s, what do you get? You get a 0. For all other combinations, you would get a 1. 4 input NAND gate expression, mathematical expression, what will happen? Well, basically it is F equals to A dot B dot C dot D an entire bar over the entire expression, which indicates that of course the product of A, B, C and D is being inverted.  Well, if we have a NAND gate, we can use the NAND gate to implement an inverter in OR gate. We can use it to implement a NAND gate. We can use it to implement an OR gate. Let us see how we can use a NAND gate to implement an inverter. Let us consider a 2 input NAND gate. What happens if you connect both the inputs together? So now, if you connect both the inputs together, you can only apply a single input. Single input, what will happen? There will be 0 or 1 here. Now, if you look at the function table or the 2 table of a 2 input NAND gate, you are left with 2 options, the 0 0 option and the 1 1 option. 0 1 or 1 0 combination is not possible because you have connected both the inputs. So, what do you get when you have 2 0s, 0 0 at the input? Well, the output is a 1. What do you have when the 2 inputs are a 1 1? Of course, both the inputs are connected together. So, you have basically a 1, the output is going to be a 0. Now, what happens if you have a 3 input NAND gate and you connect all the 3 inputs together? Would you obtain an inverter? Yes, since you can only have 2 combinations, either all 3 0s at the inputs or all 3 1s at the inputs. So, what do you get when you have all 3 0s at the 3 inputs connected together? Of course, the output is going to be a 1. When you apply 1, then of course, the output is going to be a 0. Now, let us see how we can use an NAND gate to implement an NAND gate. And NAND gate basically, it is an NAND gate with an inverter connected to the output. So, if you connect another inverter at the output of a NAND gate, what happens? The 2 inverters cancel each other out and you are left with an NAND gate. How do you obtain an OR gate using a NAND gate? Well, you have to use a combination of 3 NAND gates. Now, to explain this conversion or implementation of an NAND gate using a NAND gate and the implementation of an OR gate using a combination of 3 NAND gates, let us have a look at the diagram. Let us first look at the implementation of an NAND gate using NAND gates.  The output of NAND gate 1 is shown by F1. Now, this output has to be inverted so that we have an NAND gate output. Another NAND gate, NAND gate 2 is used as an inverter. Both its inputs are connected together and they are connected to the output of NAND gate 1. Now, if you look at the function table, the output of NAND gate 2 which now has been connected as an inverter is 0 0 0 1 which is the function table or the 2 table of an NAND gate. Now, let us see how we can implement an OR gate using NAND gates. An OR gate can be alternately represented by the NAND gate symbol with bubbles at the output and the inputs. Now, if you just discard the bubbles at the input, what do you see? You see an NAND gate. What do the bubbles mean? Well, bubbles indicate an inverter. So, the 2 bubbles at the 2 inputs mean 2 inverters. So, how do you implement an inverter by connecting the 2 inputs of a NAND gate? So, the circuit which represents the OR gate is implemented by using 3 NAND gates 1, 2 and 3. NAND gates 1 and 2 are connected as inverters and NAND gate 3 is used as a NAND gate. The function diagram confirms the operation of this 3 NAND gate circuit as a OR gate. We have just looked at 2 circuits which describe the use of NAND gate to implement an NAND gate and another circuit which describe the use of NAND gate to implement an OR gate. Let us now look at the NOR universal gate. The NOR universal gate again can be used to implement an OR gate, an NAND gate, an inverter and NAND gate. So, before we describe how we can implement all these circuits, let us have a look at the NOR gate. NOR gate basically combines the OR gate and a NOR gate. So, that means if the output of the OR gate is inverted, what do you get? You get a NOR function. Let us have a look at a 2 input NOR gate. So, what are the combinations again? You have 4 combinations 0, 0, 0, 1, 1, 0 and 1, 1. What should be the output? What was the output for the OR gate for the combination 0, 0? It was a 0. Since the NOR gate is inverting the output of the OR gate, so you should get a 1. Similarly, for the input 0, 1, what should be the output of the NOR gate? It should be the reverse of the OR gate. So, the output should be a 0. Again for the combination 1, 0, the output should be a 0. And for the input combination 1, 1, the output of a NOR gate again is a 0. Symbolically, NOR gate as I present, it is very similar to the OR gate except for a bubble at the output, which indicates that the output of the OR gate is of course being inverted. How will you write this as an expression? Well, f equals to a plus b whole bar.  Multiple inputs, that means let us say 4 input, 5 input NOR gates. Yes, it is true. Let us have a look at 3 input NOR gate. How many outputs will there be? Well, there are 8 possible input combinations of 3 input NOR gates. So, we have 8 possible output values. What can happen in this? Well, for the combination 0, 0, 0, you would have a 1 output. For all other combinations, you would get a 0 output. Expressions make a significant difference in the 3 input NOR gate. Basically, f equals to a plus b plus c whole bar. Plus, as you remember, we said it does not indicate addition. It simply indicates an OR function. The bar indicates the NOR function. Let us have a look at the timing diagram. Again, let us suppose we have a 2 input NOR gate having inputs a and b and of course the output f. We apply a certain number of inputs at input a and b. Let us observe the output through a timing diagram. A sequence of 1s and 0s is applied at the 2 inputs of the NOR gate a and b as shown in the diagram. The output of the NOR gate for intervals t0 to t6 is shown to be 0. Let us see how. At interval t0, the inputs, the 2 inputs are both 1s. What should be the output? Looking at the function table of the NOR gate, the output should be a 0. Again, for time interval t1, the output, rather the input b is a 1. So, the output should again be a 0. So, if any of the 2 inputs is a 1, the output should be 0. So, if you look at intervals t2, t3, t4, t5 and t6, either both the inputs are 1s or only a single input is a 1. Therefore, the output has to be a 0. We just looked at the timing diagram of a 2 input NOR gate. Now, let us look at the NOR gate as a universal NOR gate. Why did we say it is a universal NOR gate? Well, we can use it to implement any other gate. Let us again start by implementing the inverter. So, how do you implement an inverter or an OR gate using the NOR gate? Again, if you just join the 2 inputs or the inputs, 3 inputs, 4 inputs together, you get an inverter. If you look at the function table of a NOR gate, when all the inputs are 0s, what do you get? You get a 1. When all inputs are a 1, what do you get? The output is a 0. So, basically you have implemented an inverter. How would you implement an OR gate and an AND gate using an OR gate? Well, implementing an OR gate is very simple. NOR gate, we had told you that basically it is an OR gate and the output of the OR gate is being inverted. So, if you put another inverter, the 2 inverters cancel out and you end up with an OR gate. So, NOR gate up a claim, uske inputs milade, that becomes an inverter. You just connect it to the output of another NOR gate. That gives you an OR gate. Implementing an AND gate using an OR gate would require a combination of 3 NOR gates. With that, we would be looking at a diagram, but we would be looking at this diagram in the next lecture. Let us stop for today. Today, we looked at logic gates, which are the basic building blocks in any digital circuit. We talked about the 3 gates, the basic gates, AND gate, OR gate and NOR gate. And then we talked about the 2 universal gates, the NAND gate and the NOR gate. So, we would be continuing with these 5 gates in the next lecture. See you in the next lecture. Adha Hafiz and Asalaamu Alaikum.


In many videos I've described the leap that certain game franchises take from the NES to the Super Nintendo, as either NES games put on steroids, or NES games turned up to 11, or you get the idea. Perhaps the best example of that is the leap from Super Mario Bros. 3 to Super Mario World. And really, Mario 3 is Mario World's closest contemporary to this day, so that's going to be the main comparison I'm going to make here. Where superior looking Super Nintendo platformers like Contra 3 and Super Castlevania 4 and the Mega Man X series only had anywhere between 6 and 20 something levels, Super Mario World had 96 to blow through. And with its flawless tight controls and classic Mario stylings, there's really just no other comparison on the Super Nintendo, not even its quote unquote sequel Yoshi's Island. It's just in its own universe, which is pretty remarkable considering that it's a launch title. Anyway, while I understand Super Mario Bros. 3 will always have the nostalgic edge for many people, and yeah it does do some things better, Super Mario World takes many many things that game did and makes them better. Whether it's the new items like the feather, new interactive characters like Yoshi, a slew of new enemies like my favorite Charge and Chuck, unlocking new stages on the world map like exclamation point blocks, and worlds like the Forest of Illusion which just openly screw with you, the ghost houses and those are still fun to try and figure out, and the really fun Star World stages which was another universe of difficulty compared to the rest of the game. And the main criticism I hear about Super Mario World is that the ability to fly basically breaks the game. My response is, well, kind of, but not really. Flying and staying in the air were a little bit of a tricky process, you need enough room to take off, and you need to time the backspace correctly to stay in the air evenly. And that's unlike games like Demons Crest where you literally press a button twice and you're flying anywhere you want, now that's how you break a game. But still, even if flying is a process, the criticism remains that it robs the game of its difficulty. Uh, well, you know, there's really next to no threat of death in Super Mario World anyway, flying or no. The fun in Super Mario World is not in the challenge, at least not until you get to the Star World. The fun is plowing through all 96 levels. One of my favorite things to do in this game is to just sprint straight through it on a speedrun without dying and without stopping to unlock anything else. Super Mario World is reminiscent of Super Metroid in that there's more than one way to play it. It's very speedrun friendly, or you can take the time to explore and unlock everything, or you can go straight to the Star World from nearly the beginning of the game if you'd like. You can try to get 50s at the end of every level. The game is wide open for many different styles of players.  It just goes to show the Super Mario World universe has a timelessness to it.  Going back to the NES comparison, where I give the advantage to Mario 3 is that the world themes were much stronger and much more fun. I mean, the world where everything's huge? Who doesn't love that? Really, the only memorable world theme in Super Mario World is the Forest of Illusion, where you have to keep a lookout for alternate endings to level so you can clear a path to the castle. I do wish Mario World had gotten more creative along the lines of the huge world in Mario 3, but I wouldn't blame the developers for thinking, well, we've already done that. Let's do something else, like unlocking stuff on the world map. And that makes sense to me. Where I think Mario World has a clear advantage over Mario 3 is that Mario 3 has so many auto scrolling levels. Seriously, those get so old. That's just my opinion, obviously, but I'm thankful there's only a handful of those levels in Super Mario World. Now, as far as comparing the controls, the graphics, the sound and all that stuff, they're still very close, which is a testament to Mario 3 more than anything. But still, to me, nothing beats an afternoon of a Mario World speedrun. Over 20 years later, and it's still immensely satisfying to just bulldoze your way through this game. And hey, even if you aren't into speedruns, there's a multitude of other ways you can approach this game. That's the beauty of Super Mario World.


So, we will start taking feedback from all the centres, you can go, we cannot go to each and every centre, but we will take some, we will connect some centres.  Hello sir, good morning. Yes. Sir, I think the material that you provided was excellent and most importantly the young TAs with their energetic demos and very lucid demos actually enlightened us, empowered us with new, new sandwich and that was excellent. Thank you sir. 1098. Sir, thank you very much for the concept that you have cleared particularly regarding elliptical curves. That was very difficult to understand through textbooks because the basics are very comfortably taken and we could work out various special examples regarding that. So, thank you sir for that. Hello, good morning sir. Yes. Good morning. Sir, I am Sarika Agarwal from Dronachary College of Engineering at CIDS 2016. Sir, I think no doubt the session was very knowledgeable and our participants are equipped with their knowledge of various tools like nurses and map etc. and we all are enjoyed the guest lecture from industry speakers also and more of our two participants are eagerly waiting to give a feedback and I am handing over to my two Ms. Komal Grover. Hello, good morning sir. Yes. Sir, it's my pleasure to be addressing this wonderful audience. I wish to convey our regards for allowing us to this workshop and it was a great opportunity for us to learn about cyber security. Thank you. Good morning sir. My name is Jagpal Singh Rana. I am Shri Givnaw 1316 remote center. I want to say firstly thanks to all agencies that is Ministry of HRD, IIT Bombay and Dronacharya group of institutions for conducting this wonderful and evaluating and a lot of other things we came to know about what are the actual things going on here and how we can enhance our critical working, our event theory, even we can enhance and engage and share this knowledge and information with our own colleague and with our secondary workshop was very good. It was very eye-opening and I learned a lot here. The day I received invitation from coordinator of this 1316 center, I was so much pampered that I am going to conduct a particular workshop on the particular topic which is very interesting. This is why interesting to me because I am difficulty taking e-commerce and information security systems classes in my institute. So I got thrilled and the day one when I received this message to conduct, I mean to attend this particular workshop, I was counting the hours and minutes. Every day I used to log in on my model at least 10 to 15 times in a day. So that made me so thrilled and I learned here practically though I was aware about the theory, I was discussing with my students only theoretical aspects, most of them and some of the aspects like how viruses and other malicious malware tools are getting affected your system but I came to know and I came to learn here the new things which is definitely an eye-opening. And the best part of the workshop is this workshop has even us a lot to learn to do and to excel and to help our other students to keep themselves aware with the growing need of security in cyber space. The books provided to us is very wonderful, very eye-opening and very useful. Faculty and the coordinators are so much knowledgeable and they are so much of value addition to us. I want to extend my gratitude towards one of the faculty members, that is Professor Barnard and to my coordinator, Dr. Sarika Agarwal at the Varsic Centre. Apart from this I have huge suggestions that is suggestion number one. The workshop should be conducted more frequently but on a lesser area. Area in the sense on one or two topic because savage activity is very large area. It includes web, includes networking, includes infrastructure. My suggestion is that we should conduct a topic, a workshop on the smaller area so that we can have better knowledge which actually indeed required and of course more frequently and for lesser duration. Duration should not be more than 4-5 days at the most because fully programmed at least 40 hours, within 40 hours workshop must be done. This is my own feeling, my own suggestion. This may not be suited to all and to the system. And after that, participants must play the role of individual social responsibility to increase awareness among the society, among the people, among the peers and among the students. So they must play the role of individual social responsibility as what we have learned we should share with others because everybody just cannot learn, everybody just cannot have this information. It is only through the learning and giving back to the society. That is my last point. And also I would like to thanks to all the participants and all the individuals who has done this workshop very wonderfully conducted and my sincere thanks and my gratitude to all of them who are playing the role between and behind the scene. That is foreground and background. I have once again thanks to all of the complete team, all the ministry and the concerned ministry at the IT Bombay and especially the Kronacharya group of institutions where I had done this workshop, I attended this workshop. And it pampered me so much that I am going to take, I have learned here almost 47% the total workshop. I am going to take to my back to my original organization at least by 70 to 80%. So that I can 70 to 80% what I have learned here that can be learned by 30-40% by other people in my group. Thank you very much sir. Thank you very much for your feedback. Hello, good morning sir. Good morning. My name is Sharad Kumar. I am from Bapuji reporting from the discipline electronics and communication. I am very much impressed by this course sir. And it was annoyed and new subject for me. It was a good learning at the center. I am thankful to all those who are at the IT Bombay and gave such an important and useful sessions to all of us. We remember the sessions of Mr. Joseph Murphits for the wonderful. It was a good session sir. Thanks a lot sir, especially to all the players. Mr. Barnard, Mr. Sashukumar and one more in the department and others also. I thank on behalf of this center very much. Thank you sir. Good morning sir. Good morning. On behalf of all the participants and the PhD College of Technology. First I would like to thank IIT Mumbai for organizing such a workshop. All the, almost all the theoretical sessions and laboratory sessions were interesting and informative sir. Particularly the sessions on ECC elliptical cryptography and the online banking. That's very interesting. And some more suggestions I want to, the first thing is actually we expect more mathematical concepts related to particularly cryptography and all. I think while conducting the next workshop and all if it is included it will be very useful for us because I am from mathematical background. And the research oriented also, if you highlight some of the research oriented points it will be very useful for us. The two suggestions I want to make and overall the workshop is well organized and everything are informative and very useful for us to take the classes. Actually next semester I am going to take the paper mathematics for cyber security. So it's very useful for us. A question, my feedback is that Myself Purushottam Patil from Arthipatil Institute of Technology, Shri Pur Maharashtra we all are very happy to understand the concept of various tools like wire shark, SQL injection and mapper. It is very beneficial for budding researchers like us I am also thankful to Professor Bernard for providing us the very knowledgeable books on cryptography and cyber security. Finally it is very, in our opinion, focus on research direction should be more clearly given so that we can have selection of research topic for our future research work. Once again for overall a thankful to Professor Bernard, Professor Shiv Kumar, Professor Sudarshan for sharing available knowledge to us. Thank you sir. Hello, good morning sir. Good morning. I like to thank all of the people who were involved in organizing this workshop. Let be the organizers, let be speakers and all the coordinators. It was a very fruitful session. These 10 days of workshop we came to know so many things that we were having doubts of cyber security and we will be using some concepts in our PhD courses which some of my friends are doing and it was really very fruitful and I would like to thank IIT once again for organizing such wonderful workshops and making our summer vacations fruitful. Thank you sir. Hello sir, first of all I would like to thank M.H.R.D. funded by NMACD for conducting this workshop and my special thanks to Professor Bernard and Shiv Shankar, then Professor Deepak Pathak and the technical teams like Shushant then other peoples. So overall the workshop, the feedback is very good sir and we have did all the labs effectively and in our part the workshop coordinator has given up plenty of knowledge. He helped in many lab facilities and he had done a very good job. Even from IIT Bombay they have done a very good job and overall the workshop feedback is very good sir and continue the same for future workshop also sir. Sir, first of all we would like to thank the team of cyber security for giving us such a very information rich hands on, I mean information rich sessions both in theory as well as for the lab. Special thanks to both the professors Bernard sir and Shiv Kumar sir thank you so much sir. It was very informative and yes it has enlightened all the research perspectives of our faculty here. Thank you so much sir. My name is Professor Kirka sir from Phinolax Engineering College Technology, Nathnagiri. First of all I would like to thank the entire team of IIT Bombay for organizing such a nice workshop which gives a valuable information regarding the network security not only the theoretical part but also the software issue like Wireshark dvwa that is SEM vulnerable applications, NMAPS, SNOT applications which are very interesting tools for which we can analyze the packet as well as we can analyze all the data regarding the security issues. So once again I will special thanks to Shiv Kumar sir and Sudarshan sir and Bernard sir for giving us valuable information and organizing such a nice workshop. Thank you sir. So overall workshop is nice sir the practical sessions and our explained earlier is very nice in the Yodhran Networking Concert. So thanks to Bernard sir and Shiv Kumar sir and also my suggestions is please conduct one more workshop on the next advanced topic and also in image processing sir. Thank you sir, thank you very much. Good morning sir it is Deepak Agarwal from Purnima College of Engineering all the sessions were very much informative and we have gained a lot from your sessions but in a few sessions like in NMAPS, SNOT and NSS our participants have found some problems and even sometimes I'm also not able to solve the queries so I would like to request you to provide some links on Moodle through which they can post their queries and we can expect some answers from your site sir but overall this workshop was very good and we have found it very much useful sir. Thank you sir, thanks a lot. Good morning, myself Prabhakar Dubey from the behalf of my college BNCET and thankful to all the members of the IIT Bombay which has provided us platform to join this workshop and my college also which has given us the probability to attend this workshop really this workshop is very interactive very interesting and fruitful for us all especially the faculty members who are doing their PLB who are going for higher education all are very interesting and informative so I would like to thank all the team members of the IIT Bombay who have successfully organized this workshop. Thank you. The most provided in the YouTube was not having the audio because of that there was a problem for understanding the tools like Nmap, NSS, Nord and Metasploit. I request the teaching assistants to once again upload the videos with the proper audio assistance so that we can once again understand properly our participants can be benefited. Finally I thank all the cyber security team for organizing a wonderful workshop. Thank you very much. Hello. We are very thankful for this opportunity by the MHRD and IITB for this facilitation and wonderful initiative and we have had excellent coverage of cyber security for the past ten days in a focused and comprehensive manner. A big thanks to Prof. Bernard, Prof. Shiva, Prof. Sudarshan and other facilitators for the cyber security workshop and while we have some requirements regarding assignments to be submitted we may require a requisition letter from your end to this effect to be shown to the government authorities and also to our college authorities to gather required input for the completion of the assignment and also we look forward for more inputs and enlightening workshops in the future. Thank you. Coordinator of Cyber Security and I would like to say that the earlier session in which we have learned about the exercises and the DVWA were quite good and the later one in which the SNOT, MHRD, AW State that were discussed by the TAs were pretty fast so we think that if we will have some more data, if we will have some more things about that software, then it is better for us that we can learn very new things and very new software about that thing. By the way, overall the workshop matter and the contents of all the things were very good and we are very thankful to you. Good afternoon sir. Good afternoon. I would like to thank you to MHRD, IIT Bombay and Qt StrumTech and beyond all the participants from the Qt StrumTech and the workshop is very useful and informative and there is a scope to research areas and there is the new tools also we will learn and very thanks to MHRD and all the resource persons. Mostly the tool DVWA is very much useful for us and I have to tell you an incident. I have created a couple of websites long back but for my fortunate the class site scripting attack is not made in that website but after landing this course, I tried whether class site scripting attack is there in the website or not but class site scripting attack is there in the website but after landing this course, I have changed the coding and now class site scripting attack cannot be made in that website. So I have to thank IITB for conducting such kind of workshop and moreover I have to thank Prasad Varnaat and Prasad Sevagumar for handling this workshop. Thank you. Good afternoon sir. This is Dr. Saravanan from Remote Center, Periyaram University, Punjab, Tamil Nadu. First of all I have to thank MHRD people for having such a nice arrangement of workshop on cyber security for the past 10 days. I have to also thank the team headed by Prasad Varnaat regarding this contact of this entire workshop in a very peaceful and pleasant manner. This is what we have been expecting from this particular workshop itself and overall I have been very happy with this particular workshop and in one first session of 8 day 8 day was very useful to me regarding some research directions given by our professor Varnaat regarding this plan. We have to also thank all the people involved in this particular workshop and sharing the knowledge over the cyber security for the future directions itself. And few suggestions have been from our center itself. Since Tamil Nadu colleges have been reopened and the faculty are not able to attend fully the entire workshop period throughout the day. So if you are having such a planning in future so please make note that you may be having this workshop on a certification period or some other days which are not affecting the workload of these carriers of the individual faculties. So this is one of the suggestions we can able to give from our side. So overall it is a very nice as well as very useful seminar as well as workshop for the teachers who have been empowered to make the students for our future life itself. Thank you sir. On the behalf of prestige institute of engineering in Sainte-Syndore I submit my feedback. It was my first and very new experience which had been expanding my horrid years. It proved to be a valuable important informative part of learning. The practical session was very nice. The content and presentations or especially video had it directly. The workshop helped the faculty to understand. We enjoyed and learnt a lot and hope that in future we will become part of such a wonderful and fantastic workshop once again. Thank you sir. I, Diwakar Tiwari on behalf of all the participants of remote center 125 states that is Sijata Institute of Engineering and Science is thankful to the Ministry of HRD and IIT Bombay for organizing this workshop and giving us opportunity to participate in the workshop of cyber security. I am thankful to Professor Bernard for his talk on cryptography, web security and security protocol. I am also thankful for his providing us a documentary book on network security. I am thankful to Professor Sivakumar and Professor Sudarsan for their talk on infrastructure security and database security. Professor Deepak Pathak the principal coordinator of 10KT program and very much appreciate his concept of think, pair and share and this is totally new concept for our student and here in Srijata we will also try to implement this think, pair and share. Here at Srijata this is our 16th workshop with IIT Bombay and Khadaktur. Here in Srijata the transmission of audio video was very good and they provide tea, snacks and lunch that was also good and they provide a free transport facility for the participants and I will also thankful to remote center coordinator for his administrative work and workshop coordinator for his kind help. Last but not the least I am thankful to all the technical non-technical staff of IIT Bombay who are directly or indirectly involved in this workshop and last sir I am having one suggestion can we have some workshop on PhD oriented workshop or some workshop related to paper publishing sir thank you sir, over to you. On behalf of EBET my whole hearted thanks to Cyber Security workshop team and IIT Bombay the whole workshop is very useful and very informative to us and also sessions handled by our sir Kumar sir and Bernard sir and our Sridharth sir it's very useful sir, last year also I attended Sridharth sir workshop DBMS and management system and it was a very wonderful experience to me this year also the Cyber Security workshop gives more information to us this will help us to improve our knowledge in the field of Cyber Security also my whole hearted thanks to our remote center coordinator Mr. Raj Sankar sir he had given all the support to us and he supported very well and he gave so many guidelines in the laboratory sessions very wonderful experience to us, at the same time on my suggestion if you conduct the same workshop during the vacation period means it is very useful to us because now the academic year gets very started we can't concentrate so much on this workshop so after July means it is possible to attend the workshop very actively but if the same workshop is in May or in April means it is very useful to us we can attend very actively and we can participate in very enthusiastic manner this is our suggestion this is our suggestion sir, thank you and thank you also thank you to each and every one who are directly or indirectly to make this event grand success and I would like to thank to our remote center coordinator Mr. K. Ramna sir and A.V. coordinator Mr. Vara sir and my sincere thanks to my workshop coordinator Mr. K. Vanirkumar Redesar and these people are the one who work fully and they are providing very good practical knowledge for us to implement cyber security issues in our lab in hands on way so I thank each and every one, so IIT people as well as our college management, thank to each and every one sir thank you very much sir good afternoon sir, we are very much thankful to Dr. Patak Dr. Menjes and Dr. Shiv Kumar for conducting such a useful workshop for all of us cyber security is a common talk today and entirely this workshop is very very useful for all of us we have learnt many new things during this workshop like different topics in cryptography symmetric asymmetrically cryptography different algorithms and new cryptographic tools like WACSHAD then DVWA and WACSNOT, Metropolis etc there were some technical glitches during the entire workshop but we understand that this is a this program is conducting long term distance so it is possible to have some glitches but in spite of that the program is very very nice so one thing I have to share sir we haven't yet received the book written by Dr. Barnard so we have heard that many institutes in West Bengal have already received it so we request to all the associated professors of this program to kindly look into the matter and we hope that in future we will conduct such a workshop for all of us thank you very much and at the last but not the least I was very much thankful to the program coordinator Mr. Devaditya Kundu who has taken the pain to go over to Mumbai for this course and he has done all the arrangements here to make the workshop possible and also the remote center coordinator Dr. Bonan Yurikari who has done immensely good for the last one year for conducting all the workshops possible here in Shiliguri Institute of Technology thank you very much sir and have a nice day and this is Usha from Sona College of Technology on behalf of all the faculty members here who are participants I thank Dr. Fartak, Dr. Barnard Dr. Sivakumar, Dr. Shudarshan and all the other members of the cyber security team we are immensely benefited through this program and the last time I taught this course it was different and this time I'm going to teach in a different manner including the practical aspects especially the research directions given by Dr. Barnard is very much useful to those who are working towards their PhD and I thank also Dr. Satyamuti the coordinator from our college who had taken much effort for the program to be very useful to all of us a suggestion from our team here sir we expect a programming assignment so that faculty members will get benefited it can be a group assignment and can be evaluated and we expect the continued support from IIT Bombay for the faculty members in the coming months also thank you I thank you on behalf of all our participants who are participating here for this course from GEC College Goa the course was very useful with respect to the technical aspects and the theoretical aspects the theoretical which was covered which was also shown using the practical and we could even use the to utilize the options of using the tools to know how actually it was working, things were working in practicality and tools such as webilizer, dvwa, nss were very useful and we could even actually what we can say that the analysis what can be carried out on the network which was very newly known can be really understood and tracked so that was a better part which every participant liked and the terminology of injections phishing attacks these concepts were very useful and more in detail which we can know and this was very useful for everyone thank you sir first of all I would like to thanks first for Professor D.B. Pathak which is provided by an excellent platform to us and secondly sir I would like to thanks to Professor Bernan Sir, Shiv Kumar Sir those who provide the very good session on cyber security and sir the material in dvwa dvwa is very awesome we not face any problems to installations to store the virtual environment its guidance is very easy and second things the assignments, tutorials and lectures is very awesome your book is also very useful we also recommend to the students after a long time we have we are teacher, always we teach after a long time we have students and we enjoy learn with fun and one thing we also learn peer share we have planned so many things and these are the new things we have teach we learn how to teach the students in a new way this is very good sir and thank you so much, thank you sir also Professor Shiv Kumar Sir Professor Pathak sir conducting such a nice full work on cyber security I need to thank also our work coordinator Mr. Karival Sir and lots of new things lots of idea about how to teach cyber security to the students and all the new things also be helpful and that can be good session of which conducted by the industry person also there is one suggestion from my side that can be such a workshop can also be conducted for our students also so students can know about what is the future of cyber security in India what are the scope for the food and also such workshop in the future also conducted by the IIT Bombay also we have hope for once again I am thank to the all of the PA of the IIT Bombay which give the all practical session about the all of the cyber security and we hope we got the particular response and we get more workshop from the IIT Bombay expert thank you sir Mr. Deepak sir it is our immense pleasure to be here with you from the last 10 days we have learned so many new things like network security, cyber crimes so many things we have been aware from so many things first I would like to instead of all our participants and colleagues I would like to thank Mr. Deepak sir, Shiva sir, Bernard sir and all the resource persons they give their such a talent it's very very immense pleasure to be here with you and one more thing is Mr. Shiva sir, your practical examples are very good and Bernard sir your subject is very vast and I thought that we have learned a teeny particle it is useful in our life such a great personalities all you have been shared your talent and IIT stuff you have been shared from Kashmir to Kanyakumari it's very very good thought and I would like to thank all the IIT team and one more thing is your punctuality is very good sir I want to follow you in all the aspects which is positive and any negative is also we will run into positive and I would like to thank all of the IIT members, MHRT and our PVPSIT to support all the support for us and our co-ordinators are Lakshmi Narayana sir is very supportive in all the aspects thank you one and all, thank you sir I would like to thank all the team members of IIT for such a wonderful for providing such a wonderful platform and giving exposure to many of the tools like wire shaft and tools like in such a short period of time also the session when stand to 15 minutes session from Dr. Vijay Bhatt that was also really nice to hear from and so for all this wonderful organization I would like to thank all the team members of IIT good morning, good afternoon sir the whole session was very very nice but there is one suggestion from our side if it could be some more interactive in terms of wedges or any we await for such more workshops on various platforms such direction, lecture on the research direction was very very nice it gives us a really good topic overview of good topic regarding present friends thank you good afternoon sir, the beneficiary of this workshop on cyber security from Senghi's College of Engineering Kottayam are grateful to Professor Bedna for his textbook on all his sessions especially the research directions and we are also thankful to the other academic resource persons Shivakumar, Sudarshan and Virendra Singh and industrial resource persons and we are exposed to a pool of tools on cyber security so we have two suggestions so please keep the security research forum in IIT Bombay open to all RC research aspirants so that they can interact and contribute in this field the second suggestion is all the online sessions were clear and informative and useful but the recorded videos the quality of recorded videos were not very much clear so we will take a look in the next workshop and we also appreciate our workshop coordinator Mr. Vipindas for coordinating this workshop in very effective manner thank you sir good morning sir on behalf of the OPIT I would like to thank IIT Bombay for such a wonderful workshop cyber security and I also would like to thank Mr. Vipindas and I would like to suggest two things the first one if you include the IIT in the cyber security in one module it will be better for all the participants to learn the IIT act also in the cyber security and the second suggestion is that if you include a direct interaction in the lab session from the IIT Bombay then it will be better to us from the cyber security workshop like the wire shop and the other tools of the cyber security and I would like to request one thing if you organize a recent technology from the IIT workshop from the IIT Bombay a recent technology like the cloud computing and natural programming and other kind of the recent technology then it will be better for the other participants two things from the IIT Bombay thank you sir good afternoon sir I am Suresh from Bombay engineering college first I thank the IIT Bombay and the coordinators of the cyber security workshop and also I thank our primates and the coordinators for arranging all the hospitality for this workshop and through this workshop we do not metasploit and do it every way so through these tools we can do our research activities in an effective manner and also the research direction was given by the professor Burma was useful so I thank everyone for arranging this kind of workshops I expect this kind of workshop in future also thank you afternoon first of all I would like to thank IIT Bombay for organizing this workshop for us and overall this workshop was really good especially the positive things which I would like to say is before the last session they have given us a complete introduction of what we have to do in the last session they have given a complete outline of what tools we have what are all the so we found it very easy while doing the last session and also the tools like wire shock and cvwa we were able to use all the tools last session thank you so much and we would expect similar workshops especially in any specific topic that would be helpful for us in doing research good morning sir it's my immense pleasure to share my feedback about this workshop first of all I thank Mr. Chaudy and IIT Bombay for conducting this workshop in an efficient way to study theoretically and practically skilled and also we have so many tools such as wire shock metasplite, Nmap, Nessus the main thing here is we have given we have upholded all the attacks in so many tools but we need all the attacks that should be resolved by a single tool my suggestion is to conduct this kind of workshop for the computer related areas because security is common to all areas so we have semantic security, cloud security and so many things are there we need your kind for in all the areas and also we thank Bernhard sir, Thakumar sir and Patak for giving the nice lecture on each and every area and also you are teaching assistant and moodle concept should be appreciated I think here is we are 30 participants are here and we have received only third so kindly do the needful for the remaining books thank you sir good morning sir I would like to thank Dr. Patamasi D.B. Phataksal and his team Dr. Bernhard sir Sudharsan sir, Vilendra sir and all other resource persons I also would like to thank the team available at E-studio and E-outries there is one suggestion from our remote center there I already go through some of these tools like wire cycle and learning these tools they zero is not a easy task so my suggestion is that there should be communication link between the all participants available at my center and other centers so that if they face any problem they can ask the expert at any time and they can get their quality result so please do provide some link so that we can communicate with the IT Bombay if we had any problem while using these tools because learning them is a tedious task thank you very much that was our core institute Kulapur I would like to thank on behalf of our participants in PKI to Bernhard on special thanks to Professor Pataksal and Bernhard and even the teaching assistants who have taken the lab sessions and actually we didn't know the practical session now we updated our practical knowledge and we groom our students in the practical sessions very nicely and special thanks to the IT team who conducted these sessions and we expected this same workshop in future also and one more request is from our college we didn't receive the book for this workshop so we are kindly requesting to send the book for guiding our students thank you and one more thing special thanks to our workshop coordinator Mireskar sir for this workshop wonderful nicely and cooperation is there sir thank you MGM good afternoon sir this is Shiv Prasad from MGM's College of Engineering 119 to Nanded I will start my feedback from saying this fact that I am fan of Bernhard sir the reason is the way in which he has conducted the sessions especially the sessions of cryptography the reason why I am fan of sir is the way in which he has written the book we have read the books of computer security written by other authors and the book the way in which he has written it gives us you know the early understanding the fastest understandings of the subject because the way in which he has designed the subject matter again on personal note I liked the session of professor's deductions in his that lecture he has mentioned what are the areas in which we can there is a scope of working and we can get a lot of things in particularly in the areas of computer security so those couple of sessions of research deductions were very you know what we say comprehensive this is what I liked a lot about these sessions and the sessions of access control very first session of access control by professor it was very again comprehensive and knowledge delivery another thing that we have learned from this workshop are new tools which we were not knowing those tools specifically OSEC Metasploit and all we have learned how can we conduct the practicals on these tools and the same tools we can use for our students to be teaching this subject at undergraduate layer in our college again many again thanks to professor he is always the point of inspiration for us we are director HOD we always what we say we get to listen him whenever he is coming on the AVU platform many thanks to MHRD the way they are sponsoring the project and of course the people of IIT Mumbai spending a lot of energy and you know organizing this kind of workshop on scene people behind the scene people we all thank to them and lastly we thank your coordinator professor has me sir last 10 days he has been coordinating with us for successful organization of this workshop thank you very much on behalf of the remote center one two double fare I am thankful to the team of cyber security workshop sir and we were what to say we learned a lot of tools regarding cyber security in this workshop and the session on fishing sites it was too good and the issue of books regarding cyber security by professor Bernard is very useful to us and only one request from our side sir could we get the answers for the online quiz that was posted yesterday could we get the answers for the online quiz certainly we will post them very soon so I was listening to all the feedback lot of it positive and a few suggestions I begin by thanking all of you for participating so enthusiastically in this 10 day workshop as you know we are now changing the model where we will have only 5 days of physical face to face interaction and the remaining one week work would be done online for future workshops so 10 days is a lot of time and I take the point that we must limit ourselves to vacation time so that people can attend a couple of quick comments about the books and DVDs I am very happy that the DVD is given were found useful I am sure that the remote center coordinators have made copies of these DVDs to be further given to each participant so that each participating teacher can go back and actually use these in his or her own college about the books I must confess that we could not handle the logistics properly we had placed the order early enough and the number of books that we had ordered were actually available to us the problem was that we did not know the number of participants at each remote center and that is the reason why we had to wait for a very long time very close to the final date of registration even then we did not have sufficient information please appreciate that only half the participants had registered even 3 days before the last date of registration that was the information that we relate to Delhi the people who have not received their books please leave your postal addresses with your coordinators we will ensure that the books reach you not perhaps very immediately or instantly because we have also received the remaining books here only few days ago but these books will be posted to you either from IIT Bombay or from the remote centers those remote centers which have access books please keep them with you we will inform you what to do and if there are any expenses involved in sending these books further IIT Bombay through the project funds will reimburse those expenses so I apologize for the delay but I assure you that each one of you will get a book I am so happy that you like the book Barnard has been a stalwart in this field it is not very often that Indian teachers write books so it's a very important contribution that he has made workshop for students was a suggestion made by people in fact I am trying to enthuse all my colleagues who have participated in these workshops that while they have enjoyed relating to 6000, 8000, 10,000 teachers they would probably enjoy relating to one lakh, two lakh, ten lakh students and that is what we have started offering the massive open online courses as I mentioned we have adopted the EDX platform we have been charged with the responsibility of preparing the Bharat books or India books platform so that the students can directly benefit from these courses which are offered by faculty members not necessarily from IIT Bombay alone but from good faculty members renowned faculty members at any place including in your own colleges this should start happening shortly and may I request Barnard to commit today that he will offer a MOOCs course for the students in India with his colleagues sure Barnard has said yes so let us give him a clap his course will be the next course that will be announced and very shortly when we announce the courses we will start from 1st September and we will announce that his course will be the next one to start which may be September, October November, December, January sometime Barnard. Yeah, teaching security twice. Okay, okay fine so we will do that I have noted that the recorded video quality is not good you must understand that when we transmit directly whatever is written on the whiteboard or whatever is written on the slides appears very crisp and clear to you because these slides are actually pre downloaded in your local machines and therefore they appear very crisp anything that becomes part of a video recording in terms of particularly the littering and other things will always be a bit blurred when transmitted as images that's a problem that we have we will try and improve things further without further ado today's chief guest for the valedictory function is my own colleague Professor Kannan Mawgalyar many of you would have seen him appearing in different workshops apart from the enthusiastic participant in all our activities here he is also the overall coordinator of all national mission projects which are being conducted by IIT Bombay including the T10KT project he first agreed to give this valedictory address and later one told me that he is going away to Utti and Eroad we requested him to arrange his timing such that he is at one of the remote centers during this valedictory function we have just noted that he has reached Amruta Institute another of our institutions whose avu product we use so proudly I think I had mentioned that Amruta has decided to open source the avu so all of you can in fact in future start using these tools even for your own local usage ordinarily the vote of thanks is given at the end so I will request Professor Burnard to do that when the valedictory address ends but I would like to take this opportunity to thank the faculty members here Professor Burnard himself Professor Shivkumar and I understand that Professor Sudarshan also gave a dog more importantly the industry participants who came gave very valuable inputs please understand that cyber security and for that matter most of our engineering courses need to be buttressed with lots of practice because theory alone is not adequate and I am so happy that Professor Burnard could actually use his industrial contacts and his own old students to come here and speak to all of you equally importantly I would like to thank all the teaching assistants see unlike in some other places in IIT Bombay we do not distinguish between teachers and teaching assistants anybody who does a good job of explaining things anybody who does a good job of teaching tools and sharing it with others is as good as a teacher whether it is Professor Fatak or whether it is a second year M.Tech student so I am thankful to them particularly for participating in this and contributing significantly to the workshop I would now like to switch over to Amruta institute and invite Professor Kannan Maudgalyar to kindly give his valedictory address over to Amruta On behalf of Amruta Vishwita Pidam we welcome all the dignitaries workshop team members participants from all over India to this valedictory function good afternoon Professor Fatak Professor Burnard Manes' Professor Shiv Kumar thanks for giving me this opportunity I am really delighted to be giving this valedictory address in this extremely important course where more than 5000 people have participated it is very good because every person who has undergone this course can influence can teach this material to at least 100 people so we are talking about very large scaling factor so I am really delighted to be a part of this program and as Professor Fatak mentioned I had the opportunity to give this valedictory address from anywhere in Climbutu we decided to do this from Amruta and I in fact Professor Fatak felt that I should choose Amruta and I have come here before and Amruta being a partner towards AVU software which has now become open source software makes me really happy to be here at Amruta this actually also demonstrates the power of this method that we are using just like the participants the students can come from anywhere in the world the experts also can come from anywhere in the world even the feature nodes can be at more than one place and so this is something very good this I want to say briefly about some of the thought that has gone in coming up with this you know NME ICT project national mission project that Fatak mentioned so it was the brain child of in case who was a joint secretary when he came up with this idea he was the first mission director now we have Praveen Prakash as the new director the objective of this mission has been to raise the levels of education in India and one of the things that has really happened for example when we went from 1000 teacher training program to 10,000 teacher training program what we are doing is called T10KT we started with 1000 teacher training program and because of its success Mr. Sinha urged that we should go to 10,000 teachers one of the things that it has really it has really benefited is if you if we conduct a program only for 1000 people then the number of people who can participate from any college is a small one given that our country is a large one and typically one has to wait for many years before they get an opportunity to participate in this now that it has become 10,000 teacher training program almost anybody doesn't matter what their age is whether they are 25 years old or 30 years old 35 years old anybody who wants to participate in this course can join so this is something extraordinary because if you look at our QIP courses or even 1000 teacher training program one would be about 40 years old 45 years old to go through such a course now I see we have gone through the statistics of the people who participate we see quite a few people at the lowest age group even 25 to 30 people who are able to participate and this would not have been possible had we not scale this up this is one of the not at all obvious when you just say 1000 to 10,000 what does it do the other thing of course it has also done is it has empowered half the population of our country the number of ladies who participate in our courses you know has gone to 40 percent 45 percent which is unheard of in engineering courses so that is something really good the missions the national mission on education to ICT has gone for projects of this type to make it available to large number of people our NPTEL is done in that manner it is released as open source and made available to every university student similarly our spoken tutorials available for anybody to download and use we have virtual labs we have many projects they are all of this type of course one can ask what is the point in making it available what is the point and is it really helping so I would only say that we take any college, any school anywhere in India about 10 percent of our children can do extremely well anywhere in the world of course I am choosing arbitrarily 10 percent in some colleges it could be 7 percent some official schools it could be 12 percent but if you take 10 percent of the children in our schools or colleges anywhere in India whether they are in villages or big cities they could do extremely well anywhere in the world whether it is MIT, Stanford, Caltech, Harvard Game Bridge and so on it does not matter and these children are stuck somewhere because of economic conditions and family situation and so on you give them the opportunity they will do extremely well now the point is who are these 10 percent are they the students who top the class are they the students who come first in the class so actually the answer is not clear to me for example we know that Ramanujan failed in some other courses so it is not at all clear whether the toppers are necessarily the 10 percent that I am referring to so it is very difficult to identify these people and empower them one of the solutions seems to be to make available our technology to everybody to make available our knowledge our device for example to everybody and it will reach this 10 percent and they are the people who will be empowered and they will rise up and it is through them that I strongly believe in this so although some people may not agree with me I strongly believe and we are in fact getting some fantastic things through our partner institution let me point out one project that came out of through our partner institution for example we have quoted all the NCRT books in to EPUB format to run on Akash tablet all the 215 books if the government decides to release these books as open source we have done the conversion but if the government it is a policy decision if the government decides to release it as open source then it will be available for all of our children to download and access of course one can always have a physical copy of the book at home and one can take the children can take just one tablet to school it will have all the books and at the minimum it will reduce the full bag weight by half we know how important it is and of course this is the starting point we can empower our teachers, school teachers students and so on to add content interactive material, animation assignments, all kinds of things we could do and what I want to say is this porting was done by a second year computer science BTEC student who led a team of about 10-15 people and did that and this student it is in fact he is in the fourth year he is doing his BTEC at Tastra University, Tanjavo so this is just to say that there are lots of nice things happening there are bright students in many campuses and this methodology whatever we are doing is supposed to be targeted at these children at these bright people, bright students bright faculty members and so on so I don't want to take too much of your time I want to congratulate all of you for having gone through this I would want you to now that you have learned something extremely good I would want you to use the same philosophy please share what you have learned with other people that is sharing and collaborating has been the founding principle of this mission itself whether it is NPTEL, whether it is T10KT whether it is Akash project it is collaborative nature so we would want you to follow the same thing please share whatever you have please share your resources your computers you know if you are in a college with good facility and in your neighborhood you see colleges that do not have this facility please share your resources you can conduct workshops for all your students if you have done this don't let your computers idle our workshops are only 2 hour duration conduct a workshop every day and do it for all your students if you have finished training go to the nearby colleges if you have finished that also then call your students from nearby schools you know to start with teachers from these schools invite them train them and it is through education alone we can become a developed country and we become a developed country by leaving behind 90% of our public as second class citizens second class and third class citizens if you want to become a developed country we can do it only if we can empower all our citizens so that is something that everybody can do you can do it in a small way to start with and you will be amazed how much you can do if only you work hard and if you work in a collaborative manner so with this I would like to thank once again for the opportunity given to me to give this address I wish you all the best and Jai Hind I have already talked enough I think for the last 10 days so I am not going to speak too much just maybe a few minutes here and most of you are getting ready for lunch just a couple of things first I thank you for all the kind comments that the participants have made to us and to the team over here we very much value them all the suggestions that you have given us we will try very hard to factor that in in future courses and even in this course a couple of things about this area first and foremost this is probably one of the most difficult things most of you are teaching it or at least many of you are teaching this course it is probably one of the most challenging courses that you can possibly be teaching I have taught about 10 or 15 computer science courses in the past and I find this something that even after 10 years I still keep learning and learning every semester when I teach computer architecture the learning stops or it becomes just 10 percent more every semester or 5 percent more in this case it is about 20 percent more and I never seem to think that I know enough about the subject still it is a very very vast subject and it is very very interdisciplinary you must have seen based on the sessions in the last 10 days that we have things like applied cryptography and I am talking about applied cryptography if you take real cryptography the mathematics behind it is absolutely absolutely awesome even in applied cryptography we need to have quite a bit of background in number theory discrete mathematics algorithms and so on even things like implementation issues as we have seen in today's session when you talk about security protocols it is a completely different kind of thinking and a completely different kind of mathematics there it is more logical barn logic and some things like that some people had queries on what is barn logic that is one of the things that you will need to make sure security protocols are sound then there is another aspect to cyber security which is system security there you might see things like operating systems architecture, compilers and programming languages each have a role to play and a background in these is almost a prerequisite to understanding or teaching system security then there is network security needless to say this involves a good understanding of all the networking protocols and then there is of course the big area of application security which includes web security database security etc. I agree we have not had probably the opportunity to deal with all of these areas in sufficient depth so at least we will try to introduce you to many of them or most of them but some of them got skipped along the way two things are for example cloud security it is a very interesting and new area lots of challenges in that and side channel attacks actually belongs in that and the other area is for example android security so we were thinking of a talk in that but then because we had the previous talk on web security and there were some questions on it so Shendra actually continued and discussed web security and left out some of android security so in a nutshell this is a very vast area it is very interdisciplinary and as a result it is very challenging the next major challenge is that it is also very very dynamic things change all the time there are new worms, there are new viruses, there are new vulnerabilities and just keeping up with this is a full time job let alone teaching doing research in this field is also very very very challenging the last thing I would like to conclude by saying is that because of all these challenges we would very much like to make available certain resources on our websites and probably a website dedicated to cyber security in this institute so we can update it frequently I have many things that are in progress research in progress myself Professor Shiva and other people over here Shendra etc and we would like to populate the site with some of our technical reports these are not necessarily things that we have created but work in progress the reason for this is because sometimes it takes us about several years before something gets published so the stuff on elliptic of cryptography for example was started about 3 or 4 years ago and has just been completed the final paper is about to appear in a conference next month likewise the web security thing the browser extension that I talked about is again 3 years old we would like to make things available within a few months at most a year as soon as some work, some satisfactory work has been accomplished so we would like to put some of these resources technical reports etc on a website I am currently revamping my website but maybe another website which contains the contributions of various students and faculty members so this is one of the things that we would like to do and then in conclusion I would like to thank everybody over here starting with Professor Phatak who has been really a real driver in all of this thing we owe it greatly to him for changing the face of higher education especially MOOCs and education for the masses Professor Shiva has been very very successful and cooperative in everything also Professor Sudarshan I had Professor Varendra Singh and many many other faculty special thanks to our teaching assistants they have been available almost I can say 24 by 7 any time, every time your phone numbers are with me and I keep bugging them endlessly to help I mean you cannot believe what a great help these people have been especially for example both workshops in the first workshop it was just like a two week advance notice I gave them about the tools and immediately they set things up so that everything could be demonstrated on time a very very big thank you to our M Tech students and especially the TAs in this course and finally to the organizers I am looking at Kannan she was really very good I mean I have been sort of bugging her she has also been bugging me to get things moving and Rachna and Mahendra I don't know where he is right now but he has also been very good I don't know the names of everybody out here it is extremely cooperative so a big thank you to all of them and a good luck to all of you in your career in your future God bless and Jai Hind