Happy holidays, everyone. Hello. Call to order and hold call. So I'll call the meeting to order at 9.04 a.m. Who wants to do roll call? You want? All right. Tom DeVie? Yeah. Gene Christopher? Yeah. My name's Ortman. Here. Lauren Sealy? Here. Selie. Right? Selie. Selie. Selie. I always do that. Kendra Daniels? I'm just going to name them. I thought you were naming us. I will. That makes sense. We are here. I see you for the recording. Harold, Dominguez, Kendra Daniels, Malio, Alisa Gallanart, and Kevin. All right. Thank you so much. Item number two. Group all the minutes from the November 15, 2022 meeting. Do I have a motion? Well, I sort of ran through them really fast. I didn't see anything major. So I don't think there was. I'll second. I would like to actually have a minor change to it. Oh. Oh. Well, I think it just wasn't for aid. I think if we just have a little clarification that we talk about the rent increases for residents. So it's first on that quote we're crossing will increase 7.2%. The lodge will increase 7.49%. Residents of both properties will be receiving communication saving changes. And they will have a commentary where they can reach out to representative directly. I think we might just want to say that it's a high increase and not actually a decrease directly to the residents. Yeah. Because that may have changed actually because they brought it down. Well, I guess for the minutes. Yeah. Yeah. I think it was just going to be clear. Okay. Any other changes? All right. So let's vote. All those in favor say aye. Aye. Aye. That's unanimously. Let's go on to number three public. You better to be heard. Anybody from the public? Okay. All right. Let's go on to item four organizational updates. A, advisory board and member selection update. This is just a quick statement. Just the interviews that happened, which with Arlene and Jean and staff support occurred. We made recommendations to the board of commissioners and then they held interviews for all applicants on Saturday. And then the appointments are set for the 20th. And I'm waiting to hear back from Michelle at what point the, they select to people get notified or if it's happens. Yeah. So that's all there. I was hoping to have a little more detail, but I'll have to just go back and have anything. All right. 205 development and project updates. Okay. So we've got a lot of moving pieces going on. So village place. We held a resident meeting last Monday to give an update on what's next. The schedule is still on as it was as of last March when we pushed the construction to 2024. So we chatted about the survey that we put out to residents asking for their priorities of what they would like to see in the building and then those were due Friday. They didn't collect. Yes. So we summarizing those and then just on last Thursday, the request for proposals period closes for architects. So we have interviews set up. We got five proposals. We're interviewing three between Friday and next Tuesday. What are you going to be interviewing almost to us. ALMS to us. Are you in the kind of silence? I'm in the kind of silence. Okay. Well, we had five applications, five proposals. You can tell them later. Yeah. We just double check on that because we're ranking process and process. Yeah. Thank you. So we should have a selection next week and then work on contracting in January and send that contract to the board in January as well. Generally, we asked for we're ranking based on experience with senior properties, experience with life type recent indications, you know, overall qualifications and experience with tenant in place we have. So it cost us one factor. So that is moving right along. We are speaking with the existing investor here WNC. We're working on their wishing to exit. And so we're going to go ahead and exit them early in 2023 and not do it all at the same time in November when we're going to do a new deal as well. So we're getting that sorted. We're coming at the end of the month to come walk through to walk through. And then we are doing funding applications trying to get as much funding together as possible. So you will probably see, I'll be putting out a request to neighboring communities just seeing if they already have ideas for their PAV. I know it's 2023 and often people put it out for competitive. They don't know for several months, but we know that we'll need more PAV. So we're going to see a different community. So we spoke with DOH about that. And first of all, we need to wait until we have a conceptual design and ready for our tax credits in middle and March because they basically told us, I mean, they just don't see preservation and recidivation as very transformational. And I said, well, this is the topic that I know. We've already started our marketing efforts on why that still makes sense. I wanted to put in in the very first round, which was a notice of intent to apply December 10th, apply by January 1st. When we coordinated with them, they recommended that we wait until we have everything that we're going to put in with tax credit in March. But they also, I made the case and I said, this is the absolute poster child example project for why preservation is necessary. What happens when you, there was a rehab here, but it was nothing on the interiors. It was just critical systems. And so when you don't do a rehab for 30 some years, I mean, this is the exact reason why preservation is so critical. So I'm still planning on growing in, but we don't know how successful it will be. Oh, this is good. 1990. It hasn't had an interior update since. So we're going to try. So then we're seeking another investor. Yes. Yes. So it's rolling right along. We are still on schedule. All of the architects proposals are matched up with our schedule as well. So it's looking pretty good there. And we have a market analysis happening for the CPWD building. The CPWD is interested in purchasing it. So we'll get that information and then start talks with them because we've already separated that from the deal. So lots going on. Yes. Okay. I see what you've got here. So Zinnia, this is the permanent supportive housing over by the suites. We're, they're doing gap funding. It's not a huge amount, but there is gap funding that they're looking for. And we've coordinated what the city can participate in on that. And the closing is set for about May at this point in construction right after. They're in, they're in the thick of entitlements and getting everything figured out there for final details of cycling like that sort of thing. We were shooting to have the transfer of the property happen by the end of December. In reading the option agreement, the possibility is December 31st was really the deadline for the site plan review. So we're giving it an extra month or two to sort out exactly how the I'm sorry, I'm blanking from where we were with that, but I will get you an update. Anyway, we're still training on transferring the, oh, environmental. We have to do the environmental review before the transfer can occur. So we're going to get that to Ankara for DOH. And then do the transfer of the property in its own transaction ahead of the main closing. Everything else is moving there though. We haven't heard about any new cost escalations on later cost estimates. So everything else is just plugging along for May. Lots of work going on at the Hoverland as well. So this is the land that LHDC owns. We put out, we completed the process getting developer proposals for that. We went ahead and selected developers, Penrose. And we're moving forward we're gathering a bunch of information for them through this year. And then we're going to kick off in full force next year with a goal to apply for tax credits in August. As a first round it might take more than, well, unless we go for it. We'll see. We're still sorting out. We go non-competitive or then try for February 23, 9%. We're tailoring that now. In the meantime, we're talking with our city divisions to talk about what kind of opportunities we might be able to do on the ground floor there regarding, you know, community service type things that could benefit this family hub of a building. So we're going to, we still have an approach to the Stewart family, but that is what we're attempting to do is go that route. And then, I mean, where you haven't sorted all of this, but the Stewart family, we're able to include some of these community services that a lot of that is the Stewart family's main, you know, priority as well. So we'll see what opportunities might be there. Okay. And then finally, Recovery Cafe. So we have, we're working with Recovery Cafe to do an add-on at this week's. And it is certainly not the easy route, but if we can make it work, the benefits would be so great. So we're really doing everything we can to make it work. We, you know, the investors all have to approve and we haven't, I mean, primarily they seem favorable, but they always say, but we have to go through the attorney process, etc. And so they just closed on our request for proposals for architecture services as well last week and interviewed several firms on the ninth and they're making a selection now and then the first phase of that will be the feasibility study to make sure that this really is possible to build here and we built in our exit ramp. So if it's not feasible, that can still be covered by this CBG COVID grant. That's still an eligible thing. And if we have to pivot, then they're keeping an eye out for properties to purchase just to have a plan be updated. So we're still moving forward. It's working out and we'll have a lot more information about exactly what's possible. It's a six week deliverable on that study so it should be around the beginning of February. What's going to be the funding source for the operations of the recovery cafe? That's a new thing. Recovery cafe, it's a non-profit. Oh, okay. So we would just offer them a space. Yeah, we're just going to do a hook, product, dollar, ground lease. That's okay. And then we just provide the services to the residents. Yeah, and others in the community as well. Yeah, yeah, right. So we've gone around and around on that one. I think the attorneys thought it would be easier if we didn't do the ground lease, but we did full contracting to build it and there's way too much risk for us on that side. Especially it's really more on the city side because there's costs going around. We don't frankly have the staff to manage another construction project and I just think the ground lease is cleaner. And so we're just going to go that route. So we're meeting with recovery cafe and it's Tuesday to go over all those details. So they'll fill it out. So we will grant the funds. We will support, you know, for just traditionally, you know, how we do for other grantees. We're helping them meet all the requirements, but they will have, they will be the owner of the architecture contract. I think they're eligible to apply for the other transformational homeless grants. And they also have been thinking about trying to use opioid money. I don't know what their plan is for that but obviously that's a topic. I don't know, we need to, that's what we're meeting on Tuesday to talk about all of it. That's not, because we have the first round of opioids. I think we're voting on that this afternoon. Oh, okay. So this is through the city? Or is it at our inventory to see? No, it's just the collaborative opioid dollars. Because I don't have that for you. Okay. So no, I mean they keep going the next year. Yeah. That's because we'll have a real cost estimate. Yep. Has there been anything done about the veterans place? Or is that just still kind of where on hold? Up here on Main Street? Yeah. So they're interested in it. I think it's a timing equation for us. So we would need to we need to get further down the road on Zinnia. Because it's who's in the, I mean so I talked to Mark and we need to get together with Mark and his group to start talking through that process. But it's really the residents that we have in it and how all of that's going to work and transitioning them if they're interested in buying it. So, oh, so we're not just talking office space. We're talking the units as well and all of it. Yeah. Because, I mean it's we're all dealing with similar populations and so that may make sense for our county. I mean it's only units or everything. So we have 10 units and so it's not a lot. And if we can get a cash infusion to support the broader housing authority mission but yet they're still housing people that we would house anyway then I think it makes sense but they're still focused on getting that built out there so that's part of the issue too is they want to get further along and get that operational. I will mention that the city's sustainability teams are looking for a smaller apartment complex or multiplex to do they have energy efficiency money that they need to spend and we propose Ryderwood also because Adam our the HCI's CDBG specialist this is in our wheelhouse doing rehabs for this type of thing so we can help them because they have to income qualify and they're going to find contractors who are like we have all that so we're working with them to see if Ryderwood can be their test case. Who's that? Susan. Yeah. Yeah. Is there any other questions? That was kind of a good question. We'll recover that maybe it's on standalone building or we'll be an add-on to this week's It has to be an add-on it's going to be kind of like a breezeway. But it has to officially touch the suites to be eligible for CDBG. Definitely. I wish they would take it. Yeah. That's a good question. Yeah. All right. Let's go on to number six items for input to the LHA Board of Commissioners. Okay. So we're planning on taking Zinnia's property tax exemption policy to the board on January 31st. But that's so that's just a a heads up that that would be coming but really we've had a couple of developments happen where we've had the owner of Copper Peak Apartments approach us because when they were first getting built several years ago the prior LHA Board denied them a property tax partnership because their units were they have 12% units under 50% AMI and the rest are all 60. And the requirement at the time was 100% and it's under 50%. So they didn't do it then and then now they are reaching out to see if we would consider it after the fact because I think there's a new board and we have a revised policy. So our policy as we wrote it and adopted back in February of this year does not, it's not built for anything but new development because it's really accepting the fees at closing and you can edit the number of years of the compliance period like we did four years for Christmas because that's how long we're in 15 years typically for any other project. So when we were considering this the policy as we have it which I've printed copies in case anybody wants to reference with them going over here. So I'll hand these out. Here's the policy and this is the template calculator but with Christmas filled in just so you can see it's really easier to see with the project filled in. We, the max threshold that we have written in is 20% of your units at least 20% of your units at 50% AMI or below. And so this project would not, the cover peak does not fit in. They are above the threshold as it's written. So they are making the case that we had to have 60% designated units for our financing at the time but 40% of our units serve HCV tenants much less than 50% AMI so they're asking the housing authority to partner based on the population needs served. We've been researching I mean, so why would we consider this? I want clarification. When you're saying 60% of their units, total units or 60% of the units that go to. So they have 12% of their units designated for 50% AMI or below and the remainder is for 60% AMI. Is it 100% affordable though? Yes. It's 100% affordable but that's their unit mixes. So one of the things that came up in our joint retreat with the board slash council is really getting more people to take vouchers. And so one of the things I was thinking about is you know putting a threshold a minimum threshold with the number of doctor holders that they are willing to accept and so setting you know you have to meet or exceed the number of affordable units based on our affordable housing policy which they would do and then throwing a caveat that you need to take at least 35% of your residence unit except about or among our housing or we got to figure out the language on this. The voucher holders of which the majority of voucher holders come among our housing authority are some version of that. So it'll be interesting because you can't deny about your folder necessarily but there's just some landlords that just try to avoid it as much as possible. So we can't deny the units. Yeah. Right. So the question for this group as I plan for what I'm going to present to the board January 31st maybe it's just Zinnia under our current one or do we want to think about our policy and how it's structured do we want to add in something regarding voucher holders so they would not qualify their unit mix would not qualify them currently but he's asking for it basically but would you consider the fact that 40% of our households are earning less than 50% hand on vouchers and this is not for closing this is part way through they're just there. The other thing that since this is a legislative action I would like to put in some requirements to be in the crime-free multi-family housing I would also like to have requirements about you know actually enforcing the crime-free multi-family housing needs just because I know that puts in particular issues so because it's a legislative action I would like to put in really robust requirements in terms of managing the properties that way if they don't do it then we can miss their exception and that's how many other aspects are there. So you are we should be looking at some revisions for January is what I'm hearing if they if they want to recommend that they do it I would say we load on some other revisions on this to really help us manage other issues So this partnership policy only really contemplates a fee from LH to LHA Right. So I know where you're going I think shot a the second piece of this agenda is that. Yes. So the other several things we're considering allowing this PACS exemption partnership for existing properties not just new bills adding on requirements or considering HCV or maybe actual tenant AMI one of the two and then adding on like crime free and any other things we think of the second major piece that our policy doesn't have that many other example policies do have is a right of first refusal for such a right for both right. So we have run that question to our attorney just what would it look like and what anyway the is just if we're going to be putting in giving you this benefit at the end of your compliance period if you're not going to stay affordable then we should have a right of first refusal to keep the units affordable. So we don't have that in our policy currently and I I think that when we are contemplating this early in the year when Kathy was developing this in 2021 we were really thinking our partnership agents is what we were really thinking right off the bat and now it's really mushrooming a little bit to more than just that it is a revenue source the fee is a revenue source for us at one time and then and we have an application fee that's supposed to cover our our costs to implement the partnership which really if it's at closing it's taken care of but if it's not at closing if it's in the middle of a property like this then we would have attorney fees because we have to be a special limited partner on their ownership so we make sure then they're not in this. Yep so we'll have to do all of those things that's what Copper Peak would have to do all of that it's not just that give us money and here you go here's your exemption form so there would so that's what that fee the $5,000 application fee is intended to cover those costs that we would occur, incurred because of getting runs in partnership so those were the several things I was considering to add on to this policy some things to consider we're going to add on the right of first refusal and purchase option the end of year we have clients snack foods like we're learning this now for a property that we want to go the cost to acquire the property is the same as the cost to acquire the partnership space to take over like you guys are talking about doing this one and then the way it was written was the real property value being assessed by a property riser they're valued differently actually my property and the other one is used by an ownership so something to consider if we draft these we include this and then the roper you know that just always creates a lot of issues so I would just say put a lot of thought into how we want to award it now to avoid issues at the end of the client's period are you looking at policy provisions to hold the county to address this or have you actually got a copy of our policy from our executive director because we have a lot of people asking us to do the same thing but I just know from one that we joined in 2006 it was not well written to our department so will you share yours we might have it somewhere else that would be great because we pulled some examples to start seeing what the roper language looks like I've got another question for you especially if you are coming out hungry if we're going to get into partnership with somebody that's been in existence I'd like to get feedback from the clients what is the management style of their life what is it like living there to get down to the I'd like to know what kind of environment that management are you still creating but what kind of environment is management creating because I'm not interested in linking up with somebody that's got a rotten reputation and they don't have the best reputation in town and I would like to really cover the waterfront if we're going to get involved I would say if they're a chaff or a life tech property getting their last inspection reports and their last tax credit compliance reports to see their standings with chaff because you don't want to get into a smaller building that has a bad reputation that chaff is looking for a new partner on we're part of that bad deal that's what I'm saying let's cover the waterfront before we get get involved legally because money and asset and what have you is one thing but what are we buying into and what is our leverage for improving it so are you thinking at the right of first refusal timeframe not at the head of the partnership I would do it before we got involved we've got every right to look at what their history has been we can definitely pull that out of that documentation we can pull and keep in terms of doing learning from residents at this early stage when we're thinking about the partnership that might be a little because even if we do this we're not technically linked to them we're just a special limited partner so they're not really tied to us in any way we don't own it we don't have a smart ability over their management I don't think they can give us legally tenant information so right at first refusal we could yes and we don't have to buy it if we don't want to got it but you guys are seeing where I'm going yeah sure and I think for an existing property asking for that is certainly reasonable the Chaffa documentation or whoever they're funders but you'd want to know anyway because the whole partnership would be based on them complying and if they're not complying you pull out with no detriment to you right and they most likely have to get all these people's or agencies approval to add us on as an SLP I'm just a little gun shy and anything that has LHAs right so what's the benefit to the property after closing that property tax for this property they paid $221 $258,000 that's cheap yeah it's very cheap holy have they had that much money that's just what he said he did it's just a difference between one oh jeez that's cheap yeah it is and that's the other thing is when you write in your rofer or purchase option you want it to be the tax exempt price you want it valued at tax exempt prices not market price because you want to pay more they'll make more money if they sell at market rate but we're not going to buy it what else is here oh he's got you if you're going to take your time somewhere I'm just going to digest it yeah that's great so I have a question and it's really I think probably for new development because I don't know how you can back it up and do it otherwise so one of the things that we heard quite frequently or I guess I should say I heard with interviews was the no smoking sites now I was up at Centera not too long ago and they've got a 50 foot you have to be 50 feet from the building for smoking rather than 25 if we go into new building anyway we can make it property free rather than just building free I don't know because I think you have to have so I'm going on this from an employer standpoint and I think you have to have I know as a citizen employer you have to have designated smoking sites for your employees I would be willing to bet there's something in there for multifamily if you don't allow smoking in the units you have to provide somewhere so enterprise green communities which is required for all light tech projects does not allow the encouragement of smoking on the property so we're not supposed to have a sign that says smoking area and an ashtray that doesn't mean they can't smoke on the property but we're not supposed to specifically encourage it granted that opens its own can of worms so you don't have ashtrays and you have some cigarette butts on the ground but that's a interesting part of it is the impact that you have so if you don't do it A, you'd rather smoke so then the impact that you have on the property and so one of the guys that commented against Zinnia is the adjoining property manager and what he was commenting about is that too many people from LHA are going on to the property in the old Baza and the Swedes and activities on his property primarily I think it's like smoking marijuana because you can't smoke marijuana on this property and so you got to be cognizant of that too so if you think of what if we did it at Fall River and Spring Creek then everybody leaves there and they're in the neighborhoods and so you got to kind of balance all of those issues speaking of on that he has posted in work with Sarah so he does have trespassing activated sign and they're getting signs up so we do need to tell the residents of the Swedes that if they're on that property they will be trespassed so all of these things that you have to think of but you know Molly's rights and you don't there's a game of smoking space and then it's just from us but then it's not, it's good to have an outdoor seating area that is proper, it's distance away that is a logical gathering place and it may not necessarily be an ashtray and but I think in the design of these we can design them where they're intentionally further away so that you don't have that as you're coming in now this area is interesting because the breezeway is not a lha it's DDA and so this area closes its own issues there are a rule about no smoking with a 25 feet of entrance and it is posted in the beginning of the breezeway no smoking and that's where we still smoke yes we come in we used to by all we are going to make some summary of brain injuries and stuff thanks for your feedback I'm going to start working on some red lines which you'll most likely see at the January meeting by the way your January meeting says the 17th on the bottom of this but we had shifted to the second so it's actually the 10th January 10th and when Eric gets back she'll send out our 2023 calendar appointments so I'll shoot to have some red lines for the 10th because I'll go to the board on the 31st let's go on number 2 number 7 we covered the current question partnership right yeah that was all kind of all so 7 was the resident quality of life where are we on the DDA contract for 2020 I think I know yeah so on that one so we have funding that is coming in from the transportation fund that is part of I think the contract and then we have public human service funding I believe that comes in for VIA those recommendations are coming in next week at the city council meeting and so once that's done then they'll go into that contract and we'll probably take it month to month moving forward until we get the new contract done okay so you're maintaining the service then yes sorry Vian and I are working with VIA we have VIA on all that stuff so to sign up for you for the rest of the month are we in there okay I have each LHA report of the operations are you guys in your court we've got a small bump in occupancy um Briarwood filled up and the heart zone is completely full at the moment we will be having a vacancy at the Briarwood with the residents passing As for those neighborhood we have a pending eviction there that's not listed on here Friday from the event on Thanksgiving is it here anytime Friday yes yeah it's Friday 10 o'clock um there was police activity the last night so I'm still waiting for the nose from Sarah for that unit so I don't know what happened I just said other agencies assist on my daily briefing have cameras watching let's see Fall River um some of these are PVD units so we have the streets Fall River we both have PVD units HTV is trying to fill them with the sweets we have a lot of vacancies but MHP and LHA are running into the same issues we're mailing out 20 packets and one person response so I know Tracy and I are working on the sweets to possibly start opening that waitlist every six months so that we have good active names because what MHP and us are both seeing is a lot of the people on the waitlist are homeless um they don't update their addresses or they're on general delivery they're not checking their mail their case workers have lost contact with them so by the time they come up every contact way we have is dormant but we still have to give them the weeks to week period to respond once mailing so we're both talking about different ways um like I said Tracy and I are beginning almost for the sweets we'll need to open up every six months just to keep a good list and keep those filled MHP has four units ready to go and LHA has three ready to go um managers are calling the waitlist I know Katin is calling after hours last night still trying to get people because people just aren't answering or not interested too low of income found something already not ready yet got a new page today in the way this year so yeah four to seven o'clock last night just making calls and this waitlist is currently open so here yes so we're trying to fill the down units we've added another unit at the suite seven three one two um it's taken the record for the highest meth unit when we did the eviction there was stacks of foil um in the unit meth was found in the unit tested um so that one's going to be down for a while seven one one four they are trying to get that one back online by the end of the year it doesn't have to be reported to Chapa on the eight eight twenty three as a down unit um five that one is um the we're just working out some flooring issues with our vendor and in-house just trying to figure out what's the best way to go forward um B2 we are pending their post cleaning sampling reports the first round cleaning did not get all of it um to the point we removed the door and then there is a board reporting of the unit right now um fall river same issue we think they had to go in and remove the window seals even any extra course service they could find in the unit trying to get that to pass so in terms of the people that were in these units how long were they in these units approximately I mean we're talking these are like long no so seven three one two she was there from July to December first and that was that one came in at two thousand nine hundred and fifty parts per million the suites the ones cooking um this was the last one we did where the guns were on the bed so they weren't there just a few months um some of these other ones um 108 he was there for two years he was the only occupant in that unit so and they think he was possibly cooking it before he became a boarder so in the unit years yeah um B2 she was in there for about three years um the living room and the bedroom were high but the child's bedroom was very low so yeah that you that child's bedroom was like that touched rail five she was there for a couple years but the unit had just been redone for the re syndication into the bathroom and one bedroom um so I'm just going to add on her meth so we had been we've been researching around we've talked about this some of the things coming out of New Zealand so because I looked at the website for the meth alarm in New Zealand yesterday I got a call from New Zealand and he wants to set up a meeting to talk to us so why I I've been talking to a company at our unfortunately 7312 which is my next unit it's too high for them but they have developed a set of foam cleaner where they go through and they spray the whole unit with this foam and it basically cleans all the porous surfaces and these would be once measuring in like the one to five hundred range and it should be able to clean it with not having to rip out all the cabinetry and everything else to get into compliance they're based on a room so they're working with another company out of Arvadas so we're going to maybe look at that going forward if we have another one that tests in those range that maybe that would be easier than reconstructing these, obviously reconstructing these units so that it's just a deep, deep clean with this foam. Yeah, it just depends on the cost. Yeah, so that's what I'm afraid of. I wouldn't take that on the alarm too. Are you going to prove that it works? Yeah, with the alarm, like with the whatever smoke alarm type ones we were like unless you're going to put them in our and do like a demo in a test run we don't really want to invest. How long are you going to wait for? So I'm waiting for more information. He says not long. So I'm waiting for more information from them on that and then I found a company that makes our acumen test that we do the wall swipes with, they now have a little device that you basically reads the swipes but will give you the level within like one-tenth of it. So I'm looking into that and the cost of the it's through acumen. It's the same company, it's a little black box that they have. Make sure that we talk to Sider and Vane. Okay. So we can if we're going to do it, let's just do it whole system. Okay. And I talk to Vane all the time. I record my own Veth units because Boulder County is trailing. So as soon as I get test results in I'm sending them to co-enforcement letting them know I have another down unit. So they're helping me track them because the county is backlogged I guess with all these and keeping up with them. So on these Veth units I did have a chaffa reached out to me for me because we seem to have a lot and they wanted to know why and so I talked to Sarah and Dave with the police department and they said that we're actually because we're LHA is paying attention to their crime free of reports. This is what I told chaffa is that if we get a Veth unit by law we're supposed to do something about it but a lot of landlords are ignoring it and Sarah says she's starting to see that through the crime free program that there'll be a call for something with Veth but then the landlord doesn't do their due diligence. So when I'm talking to chaffa what they're going to do because we are on top of it I send them monthly reports where we're at I send them the construction updates everything so that they can see how we're moving through each unit that though they have to report the down units at the end of the year they're not going to report them until they come back online so that they go in as correct at 8823 and not at open 8823. So basically we chaffa called us saying looks like you guys have more Veth units than most and we go we're actually being incredibly transparent and addressing it and so that is very indicative of their appreciation I think that we are trying to do a thing. So I mean the risk would be of those landlords is that doing anything they're wrenching out a unit that has high stress results and they're not even testing for it. So once you acknowledge it, you have to remediate that to do that thing. But they're working on their tenants they're not going to sue them. So you're going to get away with it. Well that's what you're seeing the rise in these meth kids on Amazon is like we're in a place the first thing I would do is get these meth tests and go in the unit. You're in hotel rooms I was thinking last time when I was traveling I was like I was going to carry the tests to the hotel rooms. We never know anymore. Any questions on the occupancy? I just have one and I just want to word this correctly. One of the people remember in our interviews that there was a person who needed help did we reach out to that person? Yes. Remember she thought she was applying for housing. I'm sorry I can't recall her name on the top. Well we don't know her name. But it's maybe something that she could work in what she's waiting with. So I think that we took her phone number to Diana and Diana reached out to her our admin. Reached out to her because she gets a lot of similar calls and so she reaches them out I'm sorry gets them in in touch with our recovery resource people. I'm sorry my words are not working. Did you gather what I was going for? Diana was working and referred to her for her senior services in Long Island if she's not a current resident to work with them to help get housing here in Long Island as well. Okay. Brief property updates not a lot to happen but we've had a lot of bingos we did year-end bingos at all the properties killer event I'd say most properties had anywhere from a 40 to a 70% turnout this room was packed on both sides around the corner sweet yesterday people were standing at the pony wall with bingo cards because there was no more sitting room so just a great event had a lot of donations from local businesses and we're still picking up more donations that they said just used for raffle prizes and stuff going into the new year some of the the post chicken donated the ruse, pump house, Pepe's taco, tangerine a lot of restaurants crack pots donated gift bags and they're still more to pick up so I mass e-mails one morning and got a great response from the city local businesses even piercings and eyebrow tattoos tell me who's doing the eyebrow tattoos because my wife is Alpecia and so she had to do that but she can't find the lady like mom her name's Jessica you gotta make sure the circle works she's at one of the tattoo shops here they were really, I would just say the team really came out for that and the businesses were so excited to do this so most of them said contact us whenever you want to do this again and we'd be happy to support Longmont we're excited and then we filled in with a lot of the smaller little regular bingo prizes midthings but we used a lot of the gift cards and everything for the blackout prizes and we were like okay let's do another round and they were like yeah and they were just cheering each other on and just the support in the room it was a blast and we had AMN over at Aspen Senior and it was I think great for those who turned up because it was after the difficult week at AMN and they felt that they were so we didn't have a lot show up they reached out to me and said thank you for inviting us this is what we want, we haven't had this in years we want to be part of the community and get back to doing stuff for this years so yeah and I think we can make swag that just says one more ball all one more ball that's what they're all like one more, just one more so it was just a lot of fun for my team we had a lot of staff out sick so I'm sick but I had a bingo team so my two assistant managers with Andre and I went around to every property doing these bingos so I got the bingo equipment back yes I got the bingo equipment it was so funny because Corinne and I counted every ball last night to make sure we got all the balls so that was awesome that was totally awesome via shopping transportation we're seeing increased signups and more participation we're still working on a few kinks but we've had three rides so Thursday is going to be the fourth ride so and I think we've got most of that we've got systems in place we've bought more bags to just be as requirements in what our residents want let's see the suites our calls for service public safety are still remaining low I think I've not even seen a call in the last week and a half there we've got the tube method it's going through the ation I did list this but we did an Arcam training with the residents there a way forward right here on Coffman came in and did a training and provided an Arcam to all the residents and let them know when to use it that you know it won't cause damage if you administer it they're not having an opiate overdose but it can work with prescription drugs it can work with this and they kind of went through this big slide to a presentation and they're going to mimic that same training at all of our properties here in 2023 and so it's part of the opiate grant and everything and funding that they get there in Arcam through the count key and that they are able to get into the hands of the residents here in Longmont so I can't send them to the residents yeah we all got in Arcam they gave me four so I have four city and my office desk store all my managers how did they all I had all all my managers take the training that day as well and two of the maintenance guys so that they know when and how to use it and the residents are the residents yeah the residents went to the training and the residents got the Narcan as well and the lady was really good Debbie over at the way and she like literally walked through scenarios and they had a guy one of their volunteers come over and they administered Narcan as well he laid all the floor and stuff and they went through the whole thing in real life so which I think was very beneficial for the sweets residents to see it and let them know it's okay to do this I'm going to hear a question just do it not much going on at Ask Meadow Senior still working on the flooring issues neighborhood we are planning that one in fiction and Chaffa did come out a couple days after that and did a walkthrough of Ask Meadow Senior and Ask Meadow neighborhood they were really impressed of the turnaround of the property we got a few write-ups for exit signs being out the lights weren't working so those are all been fixed and then a few write-ups in Corinne's unit from it was the meth unit that was redone and so we had to have freedom fire come out and just replace those two floors so all those corrections I believe have been now submitted to Chaffa anything else I think we kind of already got over and we hired for all our positions currently except for the Billy Attendant six interviews last week I do plan on making a full-time offer today to Billy Attendant and possibly a part-time just in case you hear it there's not a lot but we are getting a call here and there regarding the renewal increases and what's tended to show itself in this is I think one or two that we sent it's where individuals are qualified for a one bedroom but they're in a two bedroom and so then our rates are going up and working through those issues outside of the light of one or two weren't hearing a lot and they've been voucher holders on this too so their portion was increased by housing not by LHA it was the voucher that set up pretty much increased but I think the meetings made works because it's been pretty quiet so I think they covered everything else and you were very specific several times as to how this was going to work so yeah yeah that's what I think the crosses on the ACV side but it's your proof of this you're in this and here's this and there you go I don't know if you hear anything else we wanted to go to a one bedroom where they wanted to so yeah so I have one that the last one that was reached out she has already initiated a transfer to a one bedroom which is what her voucher is approved for yeah I don't think any of these there's been a couple where they're just one and it's like I want a two bedroom it's like sorry we're working through with housing as well even if it's Boulder County LHA whoever the voucher holder is because there is avenues if they're in a two bedroom and they do have the need for a two bedroom because of medical equipment stuff like that we can work through them and help guide them through the process any other business out there overnight it's a journey to town two and


And as you all saw just a few minutes ago the president is doing better. He slept well last night He ate his breakfast and lunch. I Fully he actually showed me his plate Didn't ask about the menu, but I did see an empty plate with crumbs and I have some guesses about what was there But didn't ask yes Brian Stelzer CNN did Joe Biden earn a gold star for his clean plate I don't think we know I Look, I don't think that that matters, right? I think what matters is we prepared for this moment I think what matters is what Dr. Shaw just laid out. Oh, did he do a big poopie in the potty afterwards too? I'm honestly surprised that none of the reporters yelled over each other to find out if he earned a gold star Even Biden supporters have to be asking questions when they're talking like this about a guy that had to be directed by a giant Easter Bunny


So since this is the most popular and widely used today, it has become the new standard which has replaced DES. DES is too old and it's gone into disuse. It's still supported on most browsers, but people are moving towards AES. The nice thing about it is based on some very interesting and simple field mathematics. How many of you are familiar with field theory? Mathematical field? So this is really based on fields, rings and fields and the nice thing is it's very simple. So simplicity is the ultimate sophistication. It's a pretty powerful, secure kind of scheme. Regular DES was not deemed to be very secure and triple DES is slow. The block size in both cases is 64. The other one is actually 128 because using it two times, actually three times but the key is the same in two cases. A more secure secret key algorithm with a larger block size is desirable. In 2001, so as I was saying, in the 1990s, many people started attacking DES and it became clear to the security community that this is not for the future. It's got another few years and after that some smart guys somewhere in the world is going to come and attack DES and all our cryptography is going to be insecure because of that. So there's a need to replace it with a new standard and so there were many proposals that came up. 15 in the semi-final list, those 15 were reduced to five. All these proposals were vigorously debated in various conferences. These came from people around the world and they were vigorously debated, the good points and the bad points and ultimately five were selected and then from the five only the one winner which is AES. That was in 2001. So that's the one that is supported today for most applications using secret key cryptography. Now you might ask me, on what basis did you choose AES? Why not something else? There were 15 guys who were quite good. So the first thing is security. Is it secure? Is the S-box design very good and secure, for example? And many other things. Cost, computational complexity. If I'm implementing this thing, many implementations will be in software, though some of the latest Intel processors also do it in hardware. But still it's implemented a great deal in software. So how fast is it? How efficient is it to implement in software and also in hardware? Algorithmic and implementation characteristics. So is it flexible enough that I can be done easily on 8-bit microprocessors on 16-bit, on 32-bit, et cetera? Can I do it easily on, say, some of the embedded processors? Can I change the key size and the block size? If I want higher security, can I change the block size to 192 instead of 128? All of these little, little features came in handy and this particular proposal had all the best features, starting, of course, with security, but also performance and flexibility. So the block size and the key size can be varied from 128, 192, and 256. The number of rounds correspondingly is either 10, 12, or 14. And it doesn't have a feastile structure. So the feastile structure is one of my slides which will be made available, but it turns out not to have that. So all the operations are invertible in this case. As mentioned before, each round has these four steps, byte substitution, row shifting, column mixing, and subkey addition. When I say addition, what do I mean? Exclusive or useful to visualize the input block and the intermediate results as a four-by-four array of bytes. So four-by-four array and each byte is eight bits, so that gives you a total of 128 bits. So now the business of table lookup. So we said that substitutions are implemented using a table. So what should this table be? Now I've got to take a quantity which is eight bits, each element of that array, and I've got to substitute by another quantity which is eight bits. For that I need to look up into a table. So what I do is, all this thing basically says, is that you've got this eight-bit quantity split up into two parts. One part is the row index, and the other part is the column index. So I've got eight bits. You take the first four bits, which is an index into the rows. If it's four bits, it can index into two rows to four or 16 rows, and likewise for the columns. So four bits for the row index and four bits for the column index, so that table will be a 16 by 16 table. And the elements of the table, how they are obtained is through some mathematics. It's basically field mathematics. You have to take the inverse of a particular element in that array and so on. So I won't get into those details, but you can read the book for a discussion of that. So this is the substitution once again. Every single eight bits, so you've got 128 bits. Every single eight bits, there are 16 of those guys. You take those eight bits and you substitute for another eight-bit quantity. How did I know what to substitute for? I look into this lookup table. How do I know where to look in this lookup table? I take the first four bits, that's a row index. I take the next four bits, that's a column index. So I've got the row index, I've got the column index. I pluck out that byte and I substitute that byte for the original byte. And I do this 16 times because that's a four by four array. So that's the basic funda in byte substitution. Row shift. So I shift each of these rows. The first row is not shifted, but the second row is shifted by I positions, the ith row in a left way. So left circular shifts. So if I've got this array, I will shift the first row by one position to the left. The second row by two positions, circular shift. Third row by three positions. That's how I implement part of the what? Every cipher should have those three things. Substitution, permutation. So this is nothing else, but a rearranging of those bits and bytes. So it must be a transposition. And in order to make it even more secure, I have another step, which is called column mixing, which uses again field operations. I multiply by a certain field, elements of a certain field. And those elements are this. So I take the state matrix that four by four matrix, which is undergone transformations as I proceed from one step to another. And I pre-multiply it by this matrix. This is a matrix of field elements. So that is not really the number zero, one, zero, two, and so on. Those are field elements in the field of two raised to eight elements. So each element of the field is a byte, which is two hex characters. So each of those things that you see over there are two hex characters or the elements of the field gf two raised to eight. And those of you who are familiar with field theory. So you do this matrix multiplication and you get the output of this third step, which is called column mixing. Very interesting operation. The interesting thing is that avalanche effect business. After a few rounds, an output will depend on all the inputs. This is a very interesting statement, which you should be able to verify. An output will depend on all the inputs. And the final step, as we mentioned before, is round key addition. You just take that four by four matrix, each element, and you exclusive or with another four by four matrix, which contains the round key. The round key is again 128 bits. So that completes one round. Each round, four steps. And how many rounds? 10 rounds. Now one thing that's important in this secret key cryptography is the use of different modes, usage modes. So you must have seen this. How many of you have seen these modes? Okay, yeah, that's an important thing. Can you tell me, before we go to the next slides, what could these modes be used for? Let's talk about some simple things. The rest of the discussion is covered in the rest of the slides or in the book. Can you give me an example of, can you first, the motivation for CBC mode? So electronic code book mode is just this thing. Let's see the picture. Nothing very great. I have the original message. I chunk it up into blocks of size, whatever that is, 128 bits. So the first 128 bits goes with the key and it becomes 128 bits ciphertext. The next thing and so on, all of course with the same key. So we have agreed on a session key, as I've explained over here on the sheet. We have agreed on a session key and I take that session key and I take each block of my message and I encrypt each block. So that's called electronic code book. I don't know why they came up with this term, but it's a historical term, ECB mode. Now, can you think of any disadvantage of this mode? Look carefully at this and tell me how you would attack it. It's the same output. Exactly. If the input is the same, the output will be the same. So for example, if I happen to know the value of P2 and yeah, suppose I find out that C2 is equal to C5. Suppose I can see the ciphertext for example, right? And I find that C2 is equal to C5. If I happen to know P2, I will know P5. Okay, so this is like a known plain text attack where I know the plain text and the ciphertext, one pair and I'm seeing another ciphertext and I'm concluding what is the plain text corresponding to that second pair. So I know the first pair, P1, say P2 and C2 and then I know C5 and I can conclude what is P5. So this is bad news. Can we do something better? And that's something better is what's called CBC mode, cipher block chaining. So instead of all this extra words, let's just look at a figure. Will that same attack be possible here? That known plain text attack, known plain text attack, will it work here also? So a comment is made, yeah, just say a comment on the mic. If two, for two different messages, if initial few blocks are same, they will get encrypted to the same ciphertext blocks. Everybody hears that? What she says is that two messages and there could be such messages like HTTP for example has very similar kinds of things like get something, something, GET and so on. So if that first part is the same in two messages, then the same ciphertext if I know in one, I know the, if I know the plain text in one, I know the plain text in the other if they've got the same thing. Is that what you said? Is that a true statement first? Why is it not true? Sorry? Yes, so that's what these guys had in mind. What they did is they injected some randomness into this algorithm that is through the IV. So your first message, you know, almost certainly will have a different IV because IV is a random number. We'll have a different IV for the first message and the second message. Like for example, I might increment the IV. And now I can't have that same attack that I talked about before that P2, C2 and P5, C5 because the inputs to that E-box in the fifth stage over here, the fifth encryption will be completely garbled because I'm exclusive or exclusive oring the input with the output of the previous stage. So that is the output of the previous stage that is chained back, that is chained forward rather, that is changed forward to the input of the next stage. The same particular output from one stage is chained or transferred to the next stage and operated upon with the plain text of that stage through an exclusive or gate, as you can see. So that serves to randomize the input. So that P5 will now be exclusive ored with what? P5 will be exclusive ored with C4. And because of that, the randomness will increase and when you see that C5, you will not be able to make any sense of it. Bit error during transmission will affect rest of the decryption process. Bit error during transmission will affect decryption of rest of the blocks. Yes. You mean an error? Yeah. Yes, yes. That is one of the disadvantages of this approach. If there is a bit error, the only thing is if there is a bit error, you can probably handle it in another layer, like TCP and so on, ask for a retransmission. But yes, that is true. Can you think of another use of this besides encryption? And it is actually used in some of the wireless protocols. The same figure is used for something slightly different. What is that? Generation of a Mac. Generation of a Mac. So remember what was Mac and what is it used for? What does a Mac stand for? Message authentication code. And what is it used for? Message authentication besides that? This is an extremely important and subtle idea. It is used for message authentication and for integrity protection. So you say integrity protector message by appending a Mac to it. Just like in your normal data communications, you append a CRC. But don't forget, security is much more complicated subject compared to reliability. If you try to use a CRC over here, it will be almost certainly hacked. You have to use something far more complicated. So one example of implementing the Mac is through this thing. How would you do that? Just think for a second. Everybody sees that? I want to compute the Mac. What does that mean? The input to this thing is a message of arbitrary size and the output is some fixed length quantity, just like your CRC, right? Your CRC is 32 bits, for example. This thing would be typically 128 bits. This Mac, it's like a checksum. If you tamper with even one bit in that message, I will not be able to verify correctly the checksum at the other end and I will immediately suspect that you have changed the cost of the T-shirt from 200 to 2000 and so on. The nice thing about this Mac and the very, very important thing is, see, here's what I would do if I'm an attacker. I change that 200 to 2000, correct? And then what? So as not to get the receiver suspicious, I change the checksum. So the checksum is correct for the new data, for the new tampered data. Everybody sees this? I'm sending a message M1, the original guy is sending a message M1 from the sender to the receiver. I'm standing in the middle and I'm trying to take that message M1, tamper with some part of it, but if I tamper with it, that checksum will not tally at the other end, right? He will verify the checksum. Always there is an idea of generating and verifying. Whenever we talk about signatures or Macs or even CRCs, you have to generate a CRC and then you have to check it. When you do a signature, obviously signature, right? You sign, you take that thing to the bank, obviously they're gonna verify it. What else are they gonna do? Verify your signature. So the signature is to be verified at the receiver end. The same thing with the Mac. So what I am saying is I think I'm very smart. So what I do is I change that message, some bits from 200 to 2000, and I change the Mac so that it's correct for the tampered message. And then I send it, so I'm the man in the middle, take the message, tamper with it, tamper with the data, tamper will change the Mac also so that he doesn't suspect that anybody has changed anything. Will it work? Just think about this. Let me ask you a simpler question. The message has only a CRC checksum, like in your ethernet, a CRC checksum. I take this frame, ethernet frame, I tamper with the message, and I change the CRC so that the guy who's verifying the CRC, the intended receiver, doesn't smell a rat. Can I change the CRC in such a way that he doesn't feel that message has been tampered with? Yes or no? Are you sure? I don't know how many of you have seen a circuit or the software to create a CRC. It uses feedback registers, linear feedback shift registers. And it's extremely easy to generate a CRC for any message. So if I have the original message, and this is the CRC, for the new message I can also generate a corresponding CRC, you know, big deal. So he will not know that I've tampered with the message. But when you come to a Mac, you want it to be cryptographically secure. That is why you use something like this. In order for me to compute the new checksum, the new Mac, on the tampered message, what is it that I need? I need the key, the integrity key that is shared between these two guys. If I don't have that integrity key, there is no way on earth, given the kinds of schemes that we have, that you can tamper with the message and change the Mac so that he doesn't get suspicious at the other end. Now one way of doing that is exactly this thing. So what I do is I take the integrity key and I operate on this, each of these blocks of plain text. So I take the first block of plain text, encrypt it, feed it back to the second block, get the output of the second block, feed it back to the next one, and so on and so forth. I ignore all those ciphertexts, C1, C2, after I've done this. I only consider the last one. And that becomes my Mac. I think integrity will be the same, right? Will be same as what? What? We can change the Mac by using the this key, integrity key. So what happens is, if A and B have to securely exchange messages, they have to agree beforehand on the integrity key. Suppose that hacker, that middle-in man, also known as integrity key then? Then of course it's insecure. That is the key thing, right? That is why those keys, when I talked about a security protocol and I said the steps are entity authentication and key exchange. And then the rest of these messages get exchanged. That first step involved negotiating a key, agreeing upon a key. So in the SSL protocol, there are two steps you must have heard of this. SSL handshake protocol and SSL record layer protocol. What is done in the handshake is entity authentication and a derivation of all these keys. How that is done, we'll talk about tomorrow. But this is one of the keys that is agreed upon in that handshake. So that K is very important that you keep it securely. If a man in the middle sees that, then of course he can start tampering with every single message. It's a vector. Yes. So that is also you transmit it and you say I'm using this. That there's nothing secret about the IV. It's just that you should change it to increase the randomness. IV is not secret. No, not necessarily. It's just the key that is secret. The IV is just changed so that you don't have those known plain text attacks and so on. You want to randomize the whole thing. Initialization, generator, and the generator are the same one. Initialization vector, you mean? And zero random, they're different things. The zero random thing is used in the context of stream ciphers. And the IV is used in all of these, including the stream cipher, but also here. So if zero random is generated at the sending type when you're ordering the instruction, so how the zero random generator at the decryption side that will generate the same value? Are you talking about this thing or are you talking about RC4? Team C for RC4. Yes, yes. What about it? At the sending side, when we are doing the encryption, so what we are doing, we are generating the zero random generator and by using that we are generating the key after that doing the encryption. No, you have the key already. The key is known to both sides. They have agreed upon it. Okay. And then they generate the key stream. But whether that zero random generator will generate the same value at both the sides? Yes, absolutely. Because the zero random sequence is a function of the key, session key, and the initialization vector. So in that first part of the security protocol, we agree upon the secret key, the session key. And the IV can be chosen randomly, but both sides have to share it. If initialization vector, if it is made secure, is there any role that it need not be secret? Can you find out an example of where if it is known it can be compromised? In fact, in the case of RC4, as used in WEP, WEP stands for Wide Equivalent Privacy, the protocol for IEEE Auto 2.11. When you use it over there, the IV is known to everybody. It's part of the frame in the clear. I will see it in every round. Yes, so everybody can see it. And as a matter of fact, if I am the recipient, I will need to compute the key stream. So I will need that value because you're changing it with every message you send. Sir, please elaborate on linear cryptanalysis and differential cryptanalysis at some point of the time. Okay, sure, sure. That is going to be a one and a half hour lecture. But I will, if we have time on one of those days, maybe Wednesday or something. It's a very interesting thing. At least linear cryptanalysis is completely discussed in this book. So if you want, you can take a good look at it. And I mean, this is a very interesting topic, cryptanalysis. And let's see whether we have time on the next class on crypto, which is, I think, on Wednesday or something. Latest reduction for what? Sorry? Latest reduction for what? Latest reduction for what? For Pandaki cryptography tax form. And lattice cryptography, I doubt we'll have time for that. I wanted to include, so if you would like to, we can talk about homomorphic encryption and lattice cryptography and so on. But again, the only problem is time constraints. Just introduction, Riva. Okay, okay. So we'll do that. In fact, if you have anything that you would like us to introduce in subsequent lectures, just one second, anything, please let us know. So if, for example, cryptanalysis is one issue or lattice cryptography or elliptic curve cryptography or whatever it is, please let us know so that we can at least make up a half an hour presentation, introduction to those topics. My simple question is, how crypto modes is differed from crypto algorithm? Sorry, crypto modes is differed from crypto algorithm. Crypto algorithm and crypto? Crypto modes is comes under algorithm or not? Oh, I see, you said mode, M-O-D. Yes. Cryptographic modes. Yes. And cryptographic, okay. So the thing is cryptographic algorithm is the basic thing. Now, all those boxes that you see over there implement the cryptographic algorithm. But as you can see, the figures will be very different. There's something called a counter mode. It's all in the slides. There's a counter mode. So the algorithm is the same, but the modes are different. And you use different modes to achieve different things. Because one may be insecure, you use another one, for example. Or one might be performance wise better. For example, there's something called a counter mode. With counter mode, you can do things in parallel. If you've got the first block, but you didn't receive the second and third blocks, you've received the fourth block, you can go ahead and start decrypting the fourth block, even though you have not received. You can't do that over here. If you look at the decryptor, until I've got one, two, three, I can't decrypt the fourth. But with counter mode, I can decrypt the fourth, even though I didn't receive two and three. So there are different trade-offs, wherein all these different modes. I brought up this one in particular, because it helps us to do something else other than encryption. And that something else is integrity protection, using a Mac. Can we use all the algorithms in different modes? Or whether it is a decrypting value for DEs? No, no, no. All the algorithms are orthogonal in that sense. You can use AES, DES, any other secret key block cipher in this thing, in any of the modes. So this is the application I already mentioned about it, to achieve confidentiality, and also to achieve integrity protection. Nothing very great about all this. So the nice thing is you achieve two things with one solution. The Mac gives you both, integrity protection and message authentication. If there's any question, just raise your hand. Secret key, the question is, how can entity authentication be done with a secret key? That's the material for tomorrow's security protocol. So this wonderful thing called a Mac has got some very interesting properties, some of which is related to the cryptographic hash. You change even one bit in the message, and the Mac looks quite different from the original Mac. There's no way for the hacker to guess what is this new Mac. Ask a question about Xbox, Xbox, because it is, we are moved on, so I'm just going back. No, no, no, no problem. The point is like you said, like a lookup table. So do we think that the security or the vulnerability is transformed to lookup tables? You already said that Xbox should be non-linear. And the design of Xbox depends on lookup table. So now the lookup table, now the vulnerability is transformed to the lookup table. So can I say like lookup table should be non-linear to design S-box? See, the lookup table is only an implementation of the S-box. I can implement it with gates if I wanted to. Yeah, can it be different like that is what I say? Who will design the lookup table that is what? Or can it be different for? So you tell me what is your substitution. Forget about the lookup table. That is just an implementation. The key thing, the thing that requires this is the design of that S function. That should be non-linear and those kinds of things. That is very, very critical. The moment you've designed it, you just implement it with any kind of S-box you give me, I can implement with the lookup table. I just have to populate that array which is stored in memory. It's just a matter of putting the values in the right place, right? How do we proof that the S-box is non-linear? How do we prove it? The S-box is non-linear. So one thing is a brute force test. You take any combination or every combination of inputs, outputs and keys, okay? And just see what it evaluates to. So for example, take bits, the input bits, there's an 8x8 box, correct? So you take bit number 3, 4 and 7. Then take outputs 1 and 5 and take some bits of the key. Now keep changing the key value, keep changing the plain text bits, and just see what is the Boolean expression. The Boolean expression is simply an expression involving exclusive ors.  If it gives it with a high bias towards either 0 or towards 1, then you're in trouble. Excuse me, sir. Who will be having some case studies? A case studies of what exactly? For fingerprints and the areas that is mentioned in the book. For fingerprinting? And areas? Case studies. We don't have them with us. We can see, we can find some. You talk about biometrics. Yeah, so biometrics was not included in this, but we'll see whatever we can do on it. Sir, is commercial AES algorithm that is implemented already or we are using the S-box design is public or private? What do you think it is? That means, can I know that what is the S-box? What do you think it is? I mean, I hope. Anybody? So his question is, is the S-box known to everybody? No. No, no. Why should it be public? It's private. Don't you think that designers would want to keep it secret? All thing is public, but operating is public. Everything is public. Everything is public. As I told you, whatever cryptographic algorithm I or anybody else comes up with in future, we are not going to keep it secret. We are going to tell the whole world and we are going to invite all you guys and your students and everybody to hack into it. And only when you hack into it for one year or three years or whatever, and not only you but everybody in the world, and you don't find any hack for it, then and only then I will raise the flag and say, yes, now this is the most secure thing. I want you to prove me wrong. I want you to find a hack. Otherwise, how do I know it's secure? And if I don't know it's secure, how can it become a standard? If I keep it secret and somebody reverse-engineers it over time and finds a hack over it, then it's all gone. That's exactly what happened in the case of some of these previous algorithms cryptographic algorithms for cell phones and so on. They kept it a secret and then within two, three years everybody figured out what is the hack for it and that's it. Then you can hack into people's conversations and all that. So they had to come up with 3G and so on and so forth. A different algorithm for 3G. And I believe AES is also used in 3G. Thank you, sir. Sorry. Sir, we used D.F. Hellman for the secret key exchange. Yeah. Is there any harm to use for that purpose RSA? For key exchange? Yeah, for the secret key exchange. Is there any harm to use RSA as a secret key exchange algorithm? Not really. There are two different ways in which you can do it. There are many different ways in which, for example, you can do key exchange. So RSA is one. D.F. Hellman is one. You can do D.F. Hellman with a femoral key exchange, with fixed key exchange. In the security and nowhere the RSA is used as a key exchange algorithm anywhere right now. SSL has provision to use RSA for key exchange. They have not given any provision for that. They have used the D.F. Hellman only. There are four different options of which two are D.F. Hellman. One is RSA. At least one is RSA. In fact, that is the most obvious way of doing it, right? If I've got a secret key to give you, a session key, I get your public key and I encrypt the secret with your public key. So can we design an algorithm for using RSA to exchange the key with a symmetric key? That's exactly what I showed you on that paper. I come up with a secret key, a session key. I get your public key from your certificate. I encrypt the session key with your public key. Now only you can decrypt it with your private key. Yes or no? Yes. And now you have it, I have it and nobody else. That's key exchange at the simplest. Sir, a question on, a question on side channel attacks. Yes. So you already said side channel attacks is used for attacking the smart cards like credit confirmations can be taken. Yeah. Yes, but nowadays credit confirmations is more secured by having a OTP. There's one time password sent to the user's mobile. So even though the hackers know the information of the credit card, they will not get the OTP. So what is the solution? OTP is another level of security. Okay. It's not like, I mean, if you break that, then what happens? So, and side channel attacks is not just applicable in that case. If I just use my smart card, for example, I give it to the, the beta. If he has the right gadgetry, which handles the side channel attacks, which can monitor timing.  Then it's all insecure. So it's not, you know, it's not like you can never launch a side channel attacks. Again, it doesn't have to be launched only on smart cards. It can even be on servers. It can be on your browser. There are side channel attacks where intelligence agencies just hear the sound of the keys that you're pressing. And they know what you're typed. Sir, in case of RSA, you said that the encryption process is faster than the decryption. Sorry, sorry. I said the other way about decryption was fast. Sorry, encryption is faster. Encryption is faster than decryption. So if the same operation is done, how the encryption can be faster? Because at both the place, same operation is an exponential. Anybody can answer that. So his question is how it's the same operation true. What is that operation called? What is that operation? Encryption key is smaller. That is why it will be fast. No, one second. Let's just analyze the question. So he says if both the operations for encryption and decryption are the same, then how can you claim that encryption is faster than decryption? So the first question is for the benefit of everybody, what is that operation in the case of RSA? Exponential. Exactly. So it's called modular exponentiation. And you must have seen all this. The time is related to the number of, you raise it to the power. So there is squareings and multiplications. Squareings and multiplications. Am I correct? Now the question is the number of squareings is the same, but the number of the number of squareings will depend on the width of that key. The width of the key, the decryption key will be as big as the modulus, 10, 24 bits. The encryption key will be much smaller. So you have to raise that thing, the encryption key or the decryption key. You have to square it and then again square it again square it and so on and so forth. You have to do it how many times? Depending on the size of that key. How many bits that key occupies? So if it occupies only 10 bits, then I only do 10 squareings. If it occupies 1,000 bits, I do it 1,024 times, which is terrible. That is why decryption is slower. Thank you. The question may be out of the scope. How we can protect the content in the website? If you are creating a website, we have to protect the content. The same problem we faced in our college. We created a website for international conference and the same website is the same layout and same contents are posted in some other website. They created some other website. So somebody has taken your content? Yeah, yeah, content as well as the same layout is taken and it is published. The website, when you saw some change and they published the website, they present the date before the 10 days before our conference date. So his question is somebody is stealing all the content of your website? Yeah, any copyright laws are there, any copyright rules and regulations are there. Can you explain that regarding the next classes? That's a good question. How do I prevent somebody from stealing the content? Yeah, yeah, that's it. So the question is whether that solution involves cryptography or involves something else? It will not be there. Some rules and regulations are there. Later I referred that in our government site. It referred that some rules and regulations are there. Before we are posting the content, we have to get the permission from the government. We have to pay money for that. For each single page, we have to pay 12,000 rupees like that. It is mentioned there. So can you tell that regarding that? Okay, so I don't know the exact rules of the government on this thing. But I can only say this much that there are in different countries there are very stringent rules about this. Your content on your web page is your intellectual property. And in general, and this is a very serious issue, I write a paper in IEEE transactions on computers and I cannot even put that paper on my website. Just imagine it's my own paper that I've written 10 years ago. But I cannot put that on my website. What I can do is I can put a link to IEEE. So you click on the link, you go to IEEE and from there you will have to retrieve that paper.  So there are very strict rules that have come up for all these things. And I'm sure you can sue the other party if they have taken exactly your content, if you can prove it is yours. Sir, the provision is an IT Act. Yes, the IT Act. Cyber life, if I want to go to Cyber Law, I need to register that site. Yes. Register this and many procedures are there. Yes. So that word registration... You should have to register yourself. So I think he's answered your question. I think you should register your site and with the content and everything. It's just like registering property. I'm sitting and I'm living in a house and I leave it for one year. Somebody comes and says it's my house. How do I prove it? If I register with the state government, then I show the registration document, then that's proof, right? It's the same thing over here. Okay, let's just continue and wrap this up. We've got about 10 minutes. We'll take more and more questions as we go along and there is a special question answer session on Wednesday. So one of the things that you can do is to write your questions, maybe on Moodle or something, post it. We'll see what are the redundant questions and we'll at least choose a subset of them or at least answer them by email and so on. Okay. So this is a very interesting statement. If it's provably secure, it's probably not. So is this such a thing as proving that this thing is pure, is absolutely secure? Answer is you better guess. So there have been attempts by different people in different universities to prove that this algorithm or this security protocol is perfectly okay. But then there are also all sorts of other problems that arise. That is why you've got SSL that has got 10 different versions. IP Sec has got so many versions. wireless security has got so many versions of wireless security protocols and so on and so forth. It's very hard to prove that something is perfectly secure. You prove it in the next day somebody comes with a bug and shows that it's insecure. I won't talk about this thing in great detail. You've seen it and if we have time we can go through the mathematics of it. But just two or three slides because I wanted to also cover the cryptographic hash and the digital signature. RSA background proposed by Rivesh Shamir Adelman way back in 1977, one of the earliest public key schemes. Diffie Helman was even earlier than this though. I think Diffie Helman was 76. Security based on so every of these crypto algorithms has a security based on some hard mathematical problem. In this case it is the problem of factorizing a very large number say 1024 bits of 2048 bits. That is the product of two very large numbers. How large are those numbers? Those factors themselves are about 512, 512 bits for example. You can't make it too small of this. It's easy to factorize the key operations are key generation. You remember the mathematics for this? Let's very briefly talk about it. P and Q are two prime numbers. P times Q is N, the modulus. E is an encryption key. How did you find E? Relatively prime to phi of N. What is phi of N?  And then D is the inverse of E modulo phi of N. So that's the basics. That's key generation. You have generated an E. You have generated a D. Encryption. Take a message, chunk it up into blocks. M to the power of E mod phi of N. Yes or no? Not phi of N. The first one was phi of N. The second one is M to the power of E mod N. And then the ciphertext that's equal to C. And at the receiver end C to the power of D mod N. So that's the basics. Refer to the books for more examples and so on and so forth. Now the uses of public key cryptography. So encrypting these servers. So as I said, you don't want to encrypt an entire message. Supposing you're sending a message which is 100 kilobytes. The time for encryption using RSA will be quite substantial and decryption will be even worse. So what you do is you encrypt the session key. And then you decrypt the session key at the other end using that person's private key. And then you use that session key for encrypting and decrypting all subsequent messages between the two of you during that session. Okay, so it's used for encrypting the session key. Anything else besides encryption? Digital signature, right? So what is a digital signature? Very quickly. Message, how do I compute the digital signature? First you take the hash. So this message can be, let's say, five kilobytes. The hash of this thing will be how much? 128 bits or 160, for example. MD5. And then you encrypt it using what? Suppose A wants to sign it. Senders private key. Signers private key. So this is the definition of a digital signature. So here's another application of using RSA. So in the case of the MAC, use a secret key cryptography. In the case of the digital signature, use public key cryptography. Why that difference? No, there's one important word that is related to the digital signature. What is that word? Exactly. So this is one property. I sign this document. I sign this deed transfer real estate deal with my digital signature. And then I deny that I signed it. So how do you verify the signature? Yeah, so just one second. We'll just go back and write this again. So this was the signature. You sign a document, send it to the bank or to some government agency. How do they verify the signature? So what do you send?  The message can be several kilobytes. This thing is 128 bits or actually not 128 because you're doing the private key operation, say 1,024 bits. Now how do you verify this signature? Signature generation, signature verification. Just like you have encryption, decryption, you have signature generation and signature verification. So what should I do? So I take the signature, so I take the signature and I check whether this is the same thing as, this is the signature, okay? I check whether this is the same thing as, I take the message, everybody sees this. So this S is all this stuff. When I do this D and E, they get nullified, so I've got H of M. And then I verify whether this operation that I do tallies with this operation. The output of this operation is the same as performing an H cryptographic hash on the message. So this is an example of the use of public key cryptography and also of the use of the cryptographic hash. Are there any questions about this? So besides the MAC, this is the next most important thing, but unlike the MAC, this also guarantees the property of non-repudiation. I cannot sign a document and tomorrow deny that I sign this. It also guarantees integrity. Yes, it guarantees authentication, so authenticity, integrity, and in addition, non-repudiation. But the cost is slightly more. The moment I go to public key cryptography, the cost is more. Notice that in the MAC, I didn't need to use public key cryptography. Either I can generate the MAC using only a cryptographic hash or using a DES or any secret key algorithm in CBC mode. I'll just briefly talk about the cryptographic hash because this is such a wonderful thing. Sir, what is the basic difference between MAC and HMAC, sir? What is the difference? So the HMAC is using the MAC twice so that you get more security. Okay, just look at the book. There is a picture of the HMAC which makes it more security. There are some very subtle attacks that cryptographers have found on the simple MAC, so they do it twice with the same key. So some very interesting ideas over here. Can we just go on for another five minutes or seven minutes? Okay. So to produce a fingerprint or digest of a block of data, so you take a large thing and this just like a fingerprint is like a representative of yourself, right? If you use biometrics, the fingerprint represents you sort of. The same thing over here. The cryptographic hash, which is a 128-bit or a 160-bit quantity, in some sense represents that message. So to produce a fingerprint or digest of a block of data, the block of data can be a message. It can be a document, et cetera. For a given hash function, the size of the digest is fixed, though the input can be of arbitrary size. Now some very interesting properties, and you should really think about these properties. We won't have time to discuss them in great detail, but think of why these properties are so important, because you've heard of hash functions in so many contexts, like algorithms, data structures, databases and so on, but this is a completely different animal. Why is this so important? The cryptographic hash. So given an x, it is easy to compute h of x, but given a y, it is computationally infeasible to find an x such that h of x is equal to y. So this is the noninvertibility property or the one-way property. Given an x, I can compute h of x, but given h of x, it's impossible for me to find one value of x that has that same h of x. Weak collision resistance, given an x, it's computationally infeasible to find some z such that h of x is equal to h of z. So this is a weak collision resistance property and a subtle difference between weak collision resistance and strong collision resistance. So I'm saying this is a slightly harder problem for you, but I'm giving you a simpler problem. I'm not giving you an initial x. I'm saying you have the liberty to choose any x you want, and can you find any two x's, x1 and x2 are challenged to you? Find any two x's, x1 and x2, such that the cryptographic hash of x1 equals the cryptographic hash of x2, and this is called strong collision resistance. So the hash designer has to guarantee that these three properties at the very least are satisfied. And as I said before, you want to verify why these properties are so important. So pictorially, you can think of it this way. It's easy for you to go. So this is a mapping. The hash function is basically a mapping from a set of messages. Of course, messages can be of arbitrary length. So the set on the left-hand side is an infinite set, and the set on the right-hand side is, for example, how many elements? Two raised to 128. Because 128 bits, there are two raised to 128 possible hash values. So each of these things on the left will map to one thing and exactly one thing on the right-hand side, though there is no guarantee that you obviously not. You might have something else that maps to that. So understand the difference between this. There could be two things on the left-hand side that both map to the same value on the right-hand side, because the left-hand side is infinite, and the right-hand side is finite. The only problem is you simply cannot find it. It's like saying there is a very good probability that life exists on another planet, and there are billions of other planets and stars. Still, if you try to find it, we can't find it. It's the same thing over here. There are many other guys on the left-hand side that map to the same guy on the right-hand side. Still, if you try to, you cannot find it. So that's the beauty of this cryptographic hash, because of the way it's designed. This is the one-way property, and the other property, for example, over here, weak collision resistance. There is no way, given one of these values, if it's the top one, you can't find another one that maps to the same thing. So this is the property of weak collision resistance. So because of these properties, it's because of this that the digital signature is so secure. Now, think what is the meaning of that statement. Suppose these properties did not exist, then you can forge somebody else's signature, which is very bad news. The whole of e-commerce and banking, internet banking, et cetera, depends on this, on the cryptographic hash and on public key cryptography and secret key cryptography. If you can come up with a scheme that defeats all this, these properties, then we are in trouble. And so some properties to create a digest of a message without even signing it, just create a digest. So there are certain files, for example, you will store the MD5 hash of that file for integrity purposes. So that's one basic application to create a Mac. So the Mac that I showed you before uses secret key cryptography to create it. You can also create a Mac using just a cryptographic hash and using, how do I create a Mac? Without using CBC. So encrypting it, so I take the message, I compute the hash of the message, and then encrypt it using a secret that we share. So that is one way of computing the Mac. So there are two ways using the CBC mode and using the cryptographic hash. The CBC mode doesn't need to use the hash. But the digital signature needs to use the hash, as I've shown over there. So for integrity, authentication, and non-repudiation. So this is the Mac. I take, so actually the Mac can be computed this way. You don't need secret key cryptography. It is H of M concatenated with the secret key. Just look at how beautiful this thing is. And the cryptographic hash isn't very time consuming. So very fast, I can integrity protect the message. What do I do to integrity protect it? I take the message, concatenate it with the secret that we have shared. We've agreed upon the secret now. Concatenate it, and then take the cryptographic hash. So that is the Mac. So one way of computing the Mac, the other way was the CBC mode. Any questions about this? Very important. How do I compute the Mac? Two ways, using the cryptographic hash and the other way, encryption using CBC mode. How do you verify the Mac, just like you verify digital signature? What would you do? In words, you take the message. So what is sent to you is the message in the clear. I'm not even talking about encryption and all that. Send the message in the clear and send the Mac. So I take the message. I have got the secret because the two of us share it. Concatenate the message and the secret, compute the hash, and then check whether it's the same hash that he sent me. If it is, then there has been no tampering, and it's from the right guy. Both, two things in one. You guarantee both integrity and authentication, message authentication. What a beautiful idea. And in the case of digital signature, all three. Integrity, authentication, and non-repudiation. Now verify that the signature is defined by us in the sheet, satisfies all these properties. This is exactly what you want for your manual signature, correct? It should be authentic. You take me, you bring a check that you have signed to the bank. I need to make sure that it is really your signature. It should not be forgible. Some great artist who can mimic your signature has not signed it. So it might be your signature, but this great artist can mimic anybody's signature. How do I guarantee that? You see the difference between point one and point two? Authentic signature means it looks like your signature. Point two means you have signed it, not some artist who can mimic your signature. It should not be possible to repudiate a signature. I'm going to sign a check for you, one lakh, and tomorrow I say I didn't sign it. It should not be reusable. I give you a check of 500 rupees, and then you put it on some other check and put my name on that saying you gave me a check for 10,000. It should not be reused. Take it from here and put on some other check. And it should not be possible to alter the signed document. I gave you a check for 500 and you add two zeros. It should not be possible for you to do that. All of these things can be guaranteed with a digital signature. And verify that what I just said. All of these properties can be guaranteed with a digital signature. So potentially the digital signature is better than a manual signature. Okay, I think we'll stop at this point.