Hello everyone! Thank you for joining me for my presentation about the Ostwerk Initiative here at DEFCON 28 Safe Mode. I would like to thank you all for giving me an opportunity to show you the presentation I put together. And if you have a passing interest in amateur radio, I hope you find it interesting. Quick heads up, most talks or presentations like this are usually an expert lecturing about a topic they are very familiar with to an interested audience. This is kind of the opposite where today I'm an amateur radio enthusiast presenting more of a concept to people who know much more than I do. A concept that's very fluid and open to change right now depending on community input. Alright, let's begin. Please keep in mind that this is my first DEFCON, so this is a learning experience especially for me. If you have any questions during this presentation, feel free to ask them in the appropriate moderated channel in the DEFCON Discord server. And at the end, I hope to have not necessarily a Q&A, but more of like a moderated round table style discussion about your thoughts about this project, its strengths and what it needs. And I've never been part of something like that before, so I'm interested to see how this goes. I'm willing to take a gamble that many of you know what a lightsaber is. For those that don't, it's basically a laser sword from a popular movie franchise. In the stories, with rare exceptions, if you wanted a lightsaber of your own, you had to build it to your own exacting specifications. So where the switches are, the way it fits in your hand, the weight and the balance, it's all perfectly attuned to the builder. Well, what if ham radio could have their own version of the lightsaber? Right off the bat, what I hope to accomplish with this presentation is a way to simplify and encourage the planning and construction of amateur radio kits. If that doesn't interest you, then you are free to duck out now. It won't hurt my feelings, I understand your time is valuable. And we'll both be happier if you were spending your time by doing something that interests you. So to those of you who already have an enthusiasm for amateur radio, you're probably not going to learn anything brand new, but I want to keep some of the principles here in mind when you're elmering a new ham that wants a radio of their own. Alright, enter the open source tactical wireless emergency radio kit, or twerk, or twerk station. A twerk is a custom kit built by a radio enthusiast to operate in times of an off-grid situation. So you can build one for relaying voice messages into or out of a disaster zone, or you can set up a data network node, or keep track of contacts during a contest, or you can administer a twerk station parliament. Each kit is custom built by the owner to be dependable, not just for casual use, but especially for emergency situations as well. And it's my hope that this presentation motivates you to create a twerk station of your own, or assist someone in the creation of their own twerk station. I'd now like to walk you through a sample twerk station. It is a voice twerk station that I built that has data capabilities on board. It can't broadcast or receive data, but you could use the computer on board for contest logging or local networking. This twerk station is sealed up in a durable plastic case, and it's extremely water-resistant and dust-proof with the lids closed. There's no external access ports, so you have to open the kit if you want to charge it or hook up the antenna. Here it is open but undeployed. The keyboard, the microphone and the mouse kind of float around in there loose. The switches and thumb screws in there do a good job of keeping them from sliding around, but I still would like to add some kind of cushioning in there to avoid rattle damage. So flipping that blank panel that was in the lower part over, you'll see that there is a remote faceplate for an ID4100. Also under that panel is the fuse box and the cables that feed into the Raspberry Pi. And the lower left is the power controller, which switches automatically between external power and the lead acid batteries that are on board. And then on the right are the pass-throughs that pass through the microphone. There's pass-throughs that go for the USB and the audio cable into the Raspberry Pi. And there is USB ports that are not pass-throughs, they're just charging ports. The top left of the panel has the power controls and the power display. The switches engage the battery, the red one does. And then the black switch below selects between the main battery and the on-board backup. There's a power display that shows the voltage and amperage used by the kit, so it's easy to estimate the remaining power at current use. And here's the fully deployed torque station. Just to let you guys know, the monitor on the right is being powered off of AC power that goes to USB-C cable. So it's not being powered off the kit right now. That would be pretty trivial to do. I just need to find a reliable USB hub that is powered enough to keep all the hardware on board powered up. So my prototype kit is done for the most part, but it's actually not. The kit has a few issues. For one thing, it's really heavy. I want a long battery life and sealed lead acid batteries are cheap, but the kit can't be carried for more than a minute or two. The radio I have is a decent radio, but I want to switch over to HF bands. The kit has a big clunky antenna switch that I'm not going to use very often. And I discovered some new power pole mounts I want to incorporate into the design. So now I know what to improve. I can budget to get new batteries and a compatible charger, ditch the auxiliary battery in favor of bringing a solar panel, and upgrade the radio to an HF radio. I'll also need to design up a new mounting panel for all of these new parts. So that was version one of the kit and some of the challenges that I'll need to overcome. Now after I go over the three pillars of the Ostwork Initiative, I'll demonstrate the operation of the upgraded twerk station at the end of the video, which may give some of you ideas for the kit you may want to build. The Ostwork Initiative has three pillars that I think would make it successful. One is enthusiasm for the construction of twerk stations. A second pillar is the online platform twerkbench.org where a twerk station constructors or twerksmiths can compare notes. And third pillar is the twerksmith code of conduct. And let's get into these in detail. First off is the kit open source. Are there schematics or diagrams or build materials available online somewhere so that I can build my own copy of the kit and put my own spin on it? Second, the kit should be tactical. It should be constructed to work with other twerk stations in the event of an emergency. The kit should also have some degree of durability.  The kit should be wireless. Six hours of operation is a good ballpark and more is always better, but more means either more weight or more cost. So balance your options carefully. The kit can be used for emergencies or everyday use. If you plan on using your kit every day, be aware of heat buildup and have proper ventilation or better yet just invest in a dedicated base station maybe. The guidelines actually pretty loose one and it was added mostly because the acronym needed a vowel. Next, the kit should have a radio in it. Usually a mobile rig, a 12-volt kind of mobile rig, but it's encouraged to throw a cheap HT or other kind of walkie-talkie style radio into a power or utility kit just to have one on hand just in case. The final guideline is that everything is conveniently located into one single package. The kit has everything it needs built in by the owner and delicate components should fold into the kit for protection during transport. Alright, now let's get into the major types of twerk stations you might see. These are by no means all-encompassing, but should act as a starting point when designing a twerk station. First off is the voice twerk, a very common, easy to make kit. It can be made from like a used radio and a sealed lead acid battery in some kind of durable case. It's accessible for get-on-the-air and tech licenses. Second up is the data kit, and those are similar to the voice kits, but they have some kind of computer on board to take advantage of digital radio modes. The computer can be a Raspberry Pi or a laptop or a Surface Tablet, whatever, just some way to get to decode digital information and to get it out onto the air. SATCOM kits are designed for satellite interfacing, and they're usually paired with a special antenna. And there's CWHF or weak signal kits, and you want to be considerate of the weak signal kits because they're pretty sensitive to the EMF noise. Those are some of the main types of kits that you're probably going to interact with or build. And let's take a look at some of the support kit ideas, some of the advanced level kits, the auxiliary power kits, supply power to your twerk stations. You also need to think of a way to replenish power if there's no grid. Solar is a pretty popular option. Next up, antenna kits provide masks, feed line, and the antenna is necessary for broadcast and reception. Some kits are as simple as a spool of wire, and others have complex folding mechanisms. Troubleshooter kits are stocked with all the tools, adapters, duct tape, zip ties, everything you need to keep everyone on the air and happy. And remember to always thank your troubleshooter. And if a twerk station parliament gets too cumbersome, someone can step up as NetOps to take care of the administrative side of things during a crisis. They can act as one point of contact and direct the appointment of a power comptroller to oversee the power consumption in a multi-day grid down situation. So lots of coordination options available if you'd like. Finally, we have a few rare twerk stations. These are a couple twerk stations that you won't see in the wild that often. First off is the llama. Big and heavy, the llama is for the person that overpacks for every trip. It tries to do too much and doesn't tend to do anything very well. The rarest type of kit is the... Alright, so those were the twerk stations. Let's move on to pillar two or the online platform. This is kind of the weakest pillar for me. I am not a web expert at all. I have a lot of ideas based on stuff that I've seen online, but I don't really have a way to implement them. So this is where I am going to need the most help. But here are some of the ideas that I've got. The website should have a link to their own forums hopefully. A place people can submit photos and designs to be featured in the gallery. A place where people new to the hobby can stop in and have any questions answered. The website will also have a feature similar to PC Part Picker where you can pick out and design your own twerk station and have it tell you approximately how much power you'll need. The website will also hopefully feature a regional map that assists twerksmiths to find each other and maybe display power levels and capabilities of a particular registered region. So if you want to compete against nearby towns as to who's got the most power standing by in the event of an emergency, that would be kind of fun. One additional item would be a portal where student radio groups could design an ideal twerk station and find a place to get help with fundraiser or grant writing or sponsorships. A few more website ideas. Again, I have no idea how to implement these so this is all wishful thinking right now. The website might have a twerkathlon information and I'll discuss what that is later. The site would have not just a kit builder but a kit panel builder where people could design custom panel for their kits, drag and drop precise holes or precise cutouts for parts that they know they want in their kit. In the same vein, the site could have a makerspace locator where twerksmiths could find a local makerspace to help with tools or 3D printing or laser cutting, anything for constructing twerk stations. You know, maybe we could make some arrangements for partnerships or sponsorships or discounts or something. Finally, the site could have an online make marketplace where you could buy patches, stickers, small custom trinkets that could make your kit stand out. You won't be able to buy twerk stations because that defeats the purpose of the whole initiative. If you want a twerk station, you've got to build one yourself. The third and final pillar is one that I'm sure people will gloss over the twerksmith code of conduct, just a handful of principles that I hope people will live by if they want to build their own twerk station. Good twerksmith is courteous. If you build your twerk station properly, it should attract a little attention from people who may have a passing interest in our hobby. So be ready to be peppered with a few questions every once in a while when you're using your twerk station. Good twerksmith is competent. A twerk station is built to the exacting specifications of its creator and any shortcomings of the kit lie with the builder. So know how to operate your kit and know about how much power you have left at all times in an off-grid situation. Also know how to budget your remaining power responsibly. Good twerksmith values their community, both online and offline. Ideally, you would know a couple nearby twerk station owners and agree on a schedule to make contact should the worst happen in a grid down situation. Also see what you can do in a disaster to supply comfort and relief to those negatively affected. A twerksmith values their own personal honor. They would never cheat a contest and would never reveal the contents of the mystery box. A twerksmith shows their work. There are people out there who are interested in seeing what you've made. I know I am. What makes your kit special? How does it fit into your lifestyle? Finally, a twerksmith knows that there is always room for improvement, whether it's cheaper components or farther range, a better battery life, whatever. A twerksmith knows that their kit is never finished and it's just a jumping off point for better things. So those were the three main pillars of the Ostwerk initiative. And here are some bonus slides at the end. I'm going to go over something I came up with called the twerkathlon. And then we'll take a tour of a twerk station that I built, a llama class. So what if there was a competition where teams could show off their ingenuity and hustle? Basically a small course is set up with obstacles to climb over or struggle through that would resemble maybe a post-disaster situation. And teams of twerk station owners would try to race against the clock to carry their stations any way they want through the course. And then when they get the finish line, they use them to relay some traffic through a remote judging station at the end. Costumes and theme teams are encouraged and a reminder should go out beforehand saying that public intoxication of all types is frowned upon. All right, so here is my latest kit. There's a little red patch on the top where I adhere a suction cup antenna. There's about four latches on the kit that keeps the kit airtight, watertight, dust-proof. I still don't have a decent solution to keep everything from sliding around. I've got the keyboard here and I've got the microphone to uncoil. Check for product shifting during transport. Everything looks good. I'll get ready to mount the software radio antenna just onto the lid onto that red square of vinyl that I put on there because the suction cup doesn't adhere to the coarse plastic of the kit. So I need something smooth to stick the suction cup onto. A little GPS antenna. A little USB GPS antenna sticks to a metal clip for locking the kit shut. Antenna connector. I'll get that screwed on. All right, let's get ready to hook up the external power. I've got my Shanktronics power brigands applying all the power I need for the kit. Turn it on and I can see the display on the kit turns on. All right, let's get the Raspberry Pi fired up. I've got the power switch there next to the pass-through for the USB and the audio for the Raspberry Pi. I've got the dual monitors hooked up and oh well, I've got this USB switch which was powered on or the USB hub there was powered on. So now that the computer's booted up I'm just going to control it with the Logitech keyboard here.  It's not... The radio is receiving but it's not putting audio from the radio into the Raspberry Pi and that's a problem I really need to troubleshoot here. Moving along I can fire up GQRX which I have pre-programmed to decode the local classical radio station but the cool thing about the SDR is that I can program any channel I want to into here any channel that the SDR is able to decode. Alright, now for the moment you've all been waiting for a closer look into the SnacksS panel. So we remove the panel and inside we have an array of snacks we have a post snack treat we have some crunchy snacks we have some sweet snacks and we also have some more salty snacks and then all the snacks get tucked right back away into the SnacksS compartment and we replace the SnacksS panel I hope to incorporate some kind of magnets or maybe 3D print a latching solution for sometime in the near future. Alright, let's power down the kit I'll log off the Raspberry Pi and then flip off the power switch here that terminates power to the monitors and the Pi turn off the radio and then disconnect the battery we've been running off battery power this whole time battery power disconnected and as a safety measure I'm going to turn it from battery power to external power so in case the switch gets bumped for some reason it doesn't drain the battery and for those of you who are interested here is a kind of a blocky wiring diagram for how the kit works I've got the two ports, a solar port for power input and a 12 volt port for external power input and then the solar goes into the power work solar charge controller and then that charges the battery and then I have the big red battery cutoff switch and then that goes down to a selector switch that selects between the battery and the external power and then that feeds into the fuse block and then the fuse block shoots out the 12 volt leads to all of the hardware in there that runs off of 12 volts Alright, you've made it to the end of the pre-recorded portion If you're still interested you're welcome to visit the website twerkbench.org to see what we have so far and if you want a voice in the direction this project goes you can join the Discord community by visiting our Discord server online the link there is on our website at twerkbench.org and I'm going to do a live Q&A now and hopefully a demo if my equipment cooperates to round out my presentation time so please stick around and we can hopefully have a moderated discussion where we can share ideas and where this initiative should go moving forward Cool, so we have SwissNinja here and I'm live on a video feed and I think he's ready to give us a nice demo Before you start though I do have a starting question Is there any sort of mod or thing you've made that you've tried to make and just messed up so bad that you just said, nope this is going in the trash I have to start over No, but leading right up to this presentation the audio input that goes from my HF transceiver to the Raspberry Pi won't detect the audio signal like I know that the audio signal exists but it's not going into the Pi I want to just show off a couple of data modes that I would be able to be received on the Raspberry Pi but that won't be done in today's presentation I was curious if anyone had any quick questions or anything that maybe I didn't cover in the video or any suggestions because that looks like the chat topics are a little empty right now Did anyone have anything to ask or add? So I'm curious if anyone does anyone have any experience with working with the volunteer software team or web development team because a big part of the pillar of the initiative here is the website and the website we have right now is very basic and I'm learning web stuff as I go along but I wouldn't mind super-charging it with a couple team members Has anyone worked with a volunteer team in the past to get something like this done? I'm not aware of any personally I mean I'm curious are you also releasing all these plans and open-source stuff like GitHub as well? Oh absolutely, yes I hope that other people can join in like I said copy plans like they can take a look at the workstation I built that's kind of what the stemmed from was I saw kits online I would say that oh those are so awesome but I could never have one of those and then one day I decided to put a kit together for my father at the behest of my mom she was curious how we could all get together in the event of an emergency and I said oh well ham radio and all in one solution that they could use after getting their ham radio licenses to get on the air with me in the event of a grid down situation and so I would see the kits online and I would say oh those are awesome and then I decided to just build one myself and it was surprisingly easy and I just want to let people know that I want to remove the barrier to entry to making kits for themselves like a big one is the panel of the kit like I can actually start moving stuff around here like being able to laser cut I have a laser cutter in my garage and being able to laser cut a panel whenever I need a new one is a huge blessing but I want other people to be able to have that access to like to nearby maker spaces places where they would be able to download plans for a panel and then be able to have them cut out so that would probably be a portion of the website would be being able to coordinate people to be able to make their own things or this panel that the radio is inset in is 3D printed I've got my own 3D printer I know a lot of people that's a barrier to entry they don't have their own I'd like to be able to connect people that want to have their own inset panel mount things like I've made or that they've designed their own I want to connect them with online resources to be able to get them printed out Cool, we do have a couple of questions here from the audience One is what if you need more room for snacks I'm assuming there's going to be some sort of snack expander box or something like that Yeah, there's always you can get extra kits to put extra snacks in you can always sacrifice extra battery power get a smaller radio Right now this design of the 3D inset panel for my radio face is just kind of basically a prototype it's kind of there's a lot of wasted space around the edges you can see so it still needs refinement I hope to post the plan files online so that people can download and print them it's actually this this panel itself is on Thingiverse if you Google or if you use the search for Jigoo G90 it should pop up as one of the one of the 3D printable items and then I also hope to have like sticker templates like I like the industrial style of stickers so that's my kit some people might have something less colorful or more colorful more informative maybe more minimalist so I hope to have like vector files online available for stickers if you want to download them yourself Great, it's great to hear Some more questions coming in here What type or brand of case do you use in this kit This is a Harbor Freight Apache case I hope to put a once I've I've done some upgrades to the kit and I hope to have a completed bill of materials done once my presentation I've been prepping for the presentation here for a while and I hope to have a completed bill of materials done but the case itself is an Apache Harbor Freight case they're very affordable they're very similar to Pelican cases they come with a foam block that you can pick apart inside for cushioning parts I took the foam out so that I had greater airflow through the kit and I guess here as a DEF CON exclusive I usually don't show off the inside of my kits especially when they're under construction but if there's interest I'd like to show off kind of what's inside the kit normally I would have thumb screws on the side that I would undo but I haven't gotten around to those yet I'll remove the Snacks S panel and the wires are still kind of a mess I've got a battery a lithium iron phosphate battery that I just put in the kit last week I have a USB hub that comes out of a Raspberry Pi underneath and I need a better solution maybe some kind of little shelf to build in here to separate everything out so there's better airflow and then the radio here is in the back I have an RTL-SDR software radio that goes into the Raspberry Pi and of course I have the Snacks off to the side and a fuse block that the 12 volts come off of Cool, we got a question about maybe using magnets to hold down the panel on the keyboard like the Rayworth magnets that's something you've looked at Yeah, that would not be a bad idea at all the keyboard has a weird kind of curve to the back so I would have put like a Velcro or something maybe on there that would snap down but magnets would be a good idea too I just need a way to either epoxy or anchor the magnet to the keyboard or maybe to the box and then maybe put a plate on the back of the keyboard see, these are all great ideas that you could post to the Torx Station Discord or the forums if we ever get them up and running Absolutely, absolutely A question here on the chat but have you considered using solar for power and maybe there might be some interference with that Oh, so that was another thing that was brought up in our Discord chat a few days ago was someone had a question about solar controllers and noises and if anyone had experience with expensive versus cheap ones I actually have a solar panel on the way it's going to be here tomorrow someone posted a bargain online for one of them and I snatched up a nice folding one but yeah, so I had a couple batteries in my version one of the kit so that I'd have a lot of power and in this version two you saw the one lithium iron phosphate battery in the back that was about 1500 amp hours and I labeled a switch with 14 amp hours so that or 1500 milliamp hours, excuse me and then I have the switch labeled 14 amp hours so that I have a little cushion left over Yeah, I'd love a 15,000 amp hour battery Yeah, that would be great So I get a question here about you mentioned no selling for benches but what about individual parts I would like to have in the bill of materials links to parts that people use or when I built my computer a few years ago the PC part picker website would continually scan other websites would scour for prices and tell you who had the lower price and if there were any sales going on ideally there would be some kind of functionality that's like very, very, very far down the road for parts, ideally like I would just put my Amazon links for where I got all the parts basically all the parts of the kit what kind of kicked off the kit plan design was this red kill switch that I installed I've always loved these growing up and being able to buy them by a five pack was incredible like I love being able to buy stuff like that online these power connectors are 3D printed those were made by I found them on Thingiverse yeah most of the stuff was I was able to source online which I wouldn't have been able to do about 10 years ago so being able to source stuff online is a great a great benefit to the ham radio hobby great question from tWitch what are the temps inside the case when everything is powered on and running it depends I haven't used a heavy duty cycle I can't imagine it's very warm with just the Raspberry Pi running if I was broadcasting a lot with the radio the temps might get pretty warm I thought about putting active cooling in I've got empty space up here above the display panel if I wanted to put a couple case fans up here just to move air through I could move some of the air slots around this is basically the prototype version of this panel it's made out of MDF wood that I spray painted black I hope to source a plastic panel from the local plastic store they make a nice textured plastic a black textured plastic that I think will look really sharp but it's going to be more expensive than the MDF I want to make sure that the layout is done before I get the final panel cut yeah great that sounds pretty awesome we'll get a question here about when it comes to selecting components what part do you suggest that people don't skimp out on when it comes to parts and what parts do you think people can maybe buy the cheaper version of that is a very good question and that's actually part of the reason I kicked off the Ostwork initiative was to help answer that question for me so that I'd be able to select parts for my kits I know a lot of people out there have bought parts and they know what works and what doesn't this is a learning experience for me but it's kind of an expensive one so before I pull the trigger on an expensive solar charge controller or which I imagine if you want low noise like on the HF bands you'd probably want you probably don't want to skimp on your charging controller I've noticed a little bit of noise running the Pi I don't know if I'm going to be able to shield that if I'd be able to build a little shielded shelf maybe around the Pi where airflow could go but RF noise can't so there's lots of ideas for improving the kit and they can always be improved but I don't have any suggestions right off the bat but I would imagine probably your charging controller especially if you use expensive batteries and that's another thing you want to consider when picking parts is whether your charging chemistries are compatible when I made the first version of this kit I used lead acid batteries and then they were super heavy but I had to upgrade to well I didn't have to upgrade but I wanted to upgrade to lithium iron phosphate batteries which are lighter or a lot more expensive but they also use a different charging chemistry I can't use the lead acid charging system that I had in the old kit in this new kit so I had to budget for a new charging system for the kit that was compatible with the lithium iron phosphate batteries great yeah there's a couple comments here in twitch one person talks about if you don't want to take a charge controller taking a lot of space maybe have a different torque station that's like a power module power type torque station does all that just in its own separate box yeah that was an idea like one of the power torque stations like I want to have a power interface kit so people would be able to tap into different powers or different like electric vehicles or solar wind water like a kit that would be able to convert a variety of voltages down to the kit voltage and so yeah that's something for people to consider whether they want to build it into their kit or whether they want to carry an external kit that would house that functionality but the kits would hopefully function or be compatible not only with each other but with other torque stations as well yeah I've also started to see rise in popularity of the battery generators quote-unquote or just basically a battery box with a bunch of power distribution that you can now buy off the shelf which is kind of nice for like I just need power and I need lithium power and off grid we're going to question, yeah go ahead oh no I was going to say yeah those are great yeah I have splurged on one yet but hopefully soon question here could you talk a bit more about the antennas and or connectors used for the antennas to hook up to this kit yeah I use just the standard UHF antenna connector I've got actually probably easier if I just took off my nano-VNA here so this is a nano-VNA I have kind of Velcroed to the kit it's used as an antenna analyzer and I use this type of connector do I'm going to embarrass myself here PL259 or SO238 or 239 I mean but it's just this standard type of antenna connector and then I have a few I have a box around here with different adapter connectors for the antenna but the antenna that I like to use right now is I got from my brother a B&W AP10A I don't have the whip on it right now there's a whip that extends off the top that I can raise and lower and it also has a tunable loading coil that I can adjust for the HF frequencies to get a better reception or better broadcast on those frequencies but that just has the same type of screw that screws on to the screws on to the the kit there the bulkhead connector very nice you can always just say UHF connector in your good specific I think that's an SO I think it's SO is socket PL's plug I think is what it is oh okay so I think that's all we have for questions right now in the chat is there anything else you guys want to show or talk about no just curious if anyone has thought of any like if this is inspired anyone to make their own kit or if anyone has any ideas actually here's an idea so for in-person the ham radio village what if we could maybe start a fundraiser to make three or four torque stations for a get on the air station and then at the end to give them out to school groups so we'd have like a fundraiser kind of thing to make the stations and then and then after they're used for people to get on the air they can just be donated out like would that be something people are interested in he has something to take the pulse on you know just also just completely off the cuff pop my head and you could have a you know potentially even prior to Defcon so okay we'll build your best you know torque station and come you know into a competition yeah yeah that's that could be part of the torque castle on maybe if we if that if that ever takes off I mean it's not Defcon if there's no slaughtering irons involved maybe a build one within like an hour competition or something maybe cool well thank you for putting this presentation together and hanging out and chatting with us I think this is a oh yeah even get a comment in the chat someone says he's very inspiring so it's great to hear thank you for coming I thank you all for joining me and thank you to the staff for putting this on


couple weeks early. But I wanted to post this video in plenty of time because it is my annual Mother's Day gift guide. Similar to what I do around Christmas time, I thought it would be really nice to give you guys a video letting you know of some of my favorite products so that you could let your friends and family, wink, wink, nudge, nudge know what might be on your wish list for this year. I have six things that I am going to be talking to you about today. So let's get to the very first one. It's actually right over my shoulder here. You can see my ditto form. So ditto form is an exact copy, an exact replica of your body.  That information is sent off and a foam formation of your own body is created. And then it is turned into this lovely ditto form with all the ribbon markings and style lines and everything else that you need. Fully pinnable. The fabric that covers the ditto form is like a stretch jersey type material. So it's really easy to drape fabrics on it. It's easy to work with patterns on it. It is a wonderful, wonderful dress form if you are looking for something that is specific to your body. Now, when I say specific to your body, I don't just mean circumference measurements. I mean like when you have a shoulder that is higher than the other. If your shoulders are tilted or angled, if you have a hunched back or a sway back, it even has that my breasts are two different sizes. It has a smaller one and a larger one mimicking my breasts. It's so detailed that I can feel my hip bones on it. So I know exactly where like my high hip is. And depending on how tall you are, the ditto form will go down to, I guess mine is probably four inches or so below my crotch line. So if you're shorter than that, you will get a little bit more leg.  But it really does cover head to thigh and everything in between, truly everything in between. Ditto form is a bit of an investment and it's kind of a process to get it. I mean you have to get the scan and then they have to create it. It's not something that you can just order and it shows up in two days. So it's the perfect thing to put on your Mother's Day wish list because a bunch of people in your family can kind of pitch in and get you one really, really great gift that you absolutely love. All right. Next up, I'm also going to talk about some jewelry. I mean, what is Mother's Day was all jewelry, right? And I have been talking to you guys about Annalisa jewelry for literally for years. I have been exclusively getting and wearing their jewelry in my videos for so long. I just love their pieces. I love their mission. I love how they are carbon neutral. I love how they care about the environment. They care about the waste that they're putting out into the world. And on top of all of that, they make really beautiful jewelry that kind of like essentially the idea is they cut out the middleman. So they're able to bring us great quality jewelry from jewelers that make some of the biggest jewelry names that you've ever heard. But without the middleman, we there's no extra cost there. So the savings gets passed on to us and we would get really great jewelry for not a ton of money. They have pieces starting at $39 and then it goes up from there. Today I'm wearing super cute. Well, it's kind of like I'm wearing a butterfly and snakes, which I get is kind of odd.  But I wasn't realizing like, you know, snakes and then butterflies. I don't know. I just thought it was really fun. But it also shows you how you can go from sweet and dainty to also something really unique like snakes. I mean, who would have thought? And they have all kinds of really pretty stone jewelry. They have glittery stuff. They have simple minimalist stuff. They have big bold stuff and everything in between. So whether you are a minimalist type of jewelry girl and you don't wear a lot and if you do it's not super flashy, they have something for you. But also if you like the chunky statement jewelry, they have something for you as well. And again, super affordable, great for the environment. I absolutely love Ana Luisa. All right. Third on our list is something that I feel like every sewist needs, but not every sewist has or invests in for one reason or another. And that is garment labels. I absolutely love putting labels in my garments. It is just that extra little thing at the very end that makes it feel complete and polished and finished and professional. I use label weavers for all of my labels. I love the variety and the options that they have. I can get labels from them that look like some high end luxury brand, or I can get labels from them that look like I work at home and I make clothes by myself, you know, the hobby homemaker thing, depending on what your style is and where your clothes or the thing, the projects that you're making, where they end up, you can add little decals, you can change up fonts, you can use so many different colors. And then the bases that they have for their labels, there's a variety of those too. You have satin, which is really great for like lingerie and pajamas and things of that nature. You have vintage looking labels. You have the labels where the design is sewn in. You have the labels where the design is printed on. You have so many options. And then in addition to like a name plate label, you also have your care labels. So how to wash and take care of the garment. You have your size labels, which are so important if you ever end up donating your clothes. They really, some places require to have a size in there so they know where to put it in their store. But also if you have small children and they're growing up and you need to know is this 3T, 4T, they can kind of all start to look the same. So it's really important to have size labels in there as well. And label weavers has all of that covered. Their website is super easy to use. You can just plug in your information and a little demo of it shows up so you can see exactly what it's going to look like. You pick the color of the label itself and you pick the color of the design and you are good to go. So customer service is excellent. So if you get to the website and you're a little bit overwhelmed, fear not, they will be able to help you out with that as well. So label weavers number three on my mother's day gift guide list. All right, this next one is for all the moms who like learning new things, whether that be new things in business, new lifestyle things, new crafts, whatever it is. There is a virtual learning platform called SkillPop. If you've watched my channel before, you know that I've talked about them before because I am a SkillPop instructor myself. I have like a sewing machine basics class and then I have like our first projects class. But in addition to these sewing classes, they also have a ton, a ton of really amazing awesome classes, both craft wise and but it also branches out from that as well. They have stuff on videography, they have stuff on bread making, they have hand lettering, they have business classes, home organizing, home decorating, so many different types of classes on there. So whether or not you're doing something to fulfill, you know, your creative side or you have a real need to learn something, SkillPop has you covered. All of their classes are 20, 25 dollars. They usually last 90 minutes. Sometimes they run over a little bit and they take place every day of the week at 530 or 7pm Eastern Standard Time. So whether you're on the East Coast, West Coast, wherever you are, you can find some time to join that class. All of their instructors, like me, are very passionate about what they teach, very knowledgeable about what they teach and really, really want to help you learn something new. I know speaking from my own experience, when I have people come to my sewing machine basic class, a lot of these people have never turned on a sewing machine before and it just brings me so much joy to know at the end, they're a little less afraid of the machine and I feel like no matter what class you're taking, that's the kind of feeling you're going to get at the end. You're going to feel a little bit more confident. You're going to feel very proud if you are able to make something or if the class is a project based class, you're going to be really proud of whatever you made. And at the end of the day, you are going to learn something amazing. So check out SkillPop, find a class that you want to take, bring in if you have an adult kids, bring in your adult kids, you guys can take the class together. You and your husband, I have plenty of couples that come to my sewing classes together as couples and I just think it's like the sweetest thing ever. So make it like a date night or whatever. Lots of fun classes over at SkillPop. All right, next up on my list is something that I just recently told you guys about and I feel like I cannot talk about them enough and that is Sublime Graphics. Sublime Graphics prints PDF sewing patterns no matter what format they come in, whether it's AO, copy shop file, letter sizing, whatever it is, they are able to print that for you large format on one sheet on different types of papers. They have three different types of papers. They have a tissue paper. They have something they call tracing paper and then they have like your regular copy shop paper. So I would be remiss if I didn't let all the mothers out there know that this is something that they need to put on their Mother's Day wish list because let's be real, your moms, you're busy, you have so much going on and taping together patterns is not, there's no time for that. So I thought that sending awesome patterns to Sublime Graphics, having them come back to you already printed, already in a large format would just be that one extra kind of like boost and motivation that you would need to get started on that particular sewing pattern. All of the printing jobs are priced per job not per sheet and then there are different pricing for the different papers obviously and then if you need them to digitally combine your like letter sheets together, they call it digitally taping them but basically they take all the individual sheets and they magically, I don't know, put it in some system and it spits it out and then it's all in one sheet so there's an extra charge for that and then of course you'll pay for shipping. So there isn't added cost to it but you have to look at it like well what is that time worth to me? Your time is very valuable, if your time with your loved ones is very valuable, if you find yourself you know being pulled in a million different directions and you're not getting the sewing projects done anyways, maybe that is an investment that is worth it to you. So Sublime Graphics is truly awesome, the fact that they print on tissue paper is literally a game changer, the fact that they will digitally tape your files together if they don't, if like the pattern designer does not provide an AO or a copy shop file, it doesn't matter, they can fix that for you. They are just really really a sewers business and a sewers company and a company that cares about our time and cares about making our lives easier and I love love love companies like that so check out Sublime Graphics. All right similar to jewelry, there is a jewelry of the sewing room in my opinion and that is thimbles.  She designs thimbles that are not only beautiful and like works of art in their own right but they are also functional. They make your hand sewing so much easier and so much better because Jan takes the time to match you with a style of thimble that is best for you. It's not just the bucket thimbles that you're used to from like the prepackaged stuff at the craft store. She has I think four different styles of thimbles depending on how you hand sew, whether you're pushing at the top of your finger, the pad of your finger, the side of your finger, wherever you're pushing that needle through. She has a thimble designed for that and then all of her thimbles are sized so if you have littler fingers, fatter fingers, if you like to have a fingernail, if you keep your fingernail short, she has a size and a style that is going to give you as much of a custom experience as you can with a thimble doing it virtually. The designs like I said are truly so beautiful. She has new ones that come out all the time. She just released a whole bunch of spring ones. She's got kind of gothic ones. She's got really pretty flowers and floral ones. There's some with butterflies and dragonflies. There are really really some beautiful beautiful designs in there that she does all by hand and what I love about this as the idea for a Mother's Day gift is that it is an heirloom piece. It is something that you are maybe able to pass down again and again and again as you pass on your love for sewing and the idea of that just, I don't know, it just feels, it just warms my heart so much and it you just feel the love whenever you're using one of Jan's thimbles because you know that all the work that you're putting into it, all the energy that you're putting into it knowing that that is going to get passed down to someone that you love who then loves sewing. I don't know. This is a whole full circle idea of that just makes me so so so happy. So working with Jan is really easy but it is a bit of a process because you have to you know virtually send her pictures of your hand, measurements of your finger.  So it's kind of a fun process but again it is a little bit of a process similar to dittoform where you have to be a little bit patient but in the end you're going to get something that you truly love that fits and that makes your hand sewing projects, whatever they are, easier to do, more comfortable to do and just better all around. So thimbles for you is the pen ultimate gift idea on my Mother's Day gift guide. All right the very last item on my gift guide is the Aliso Pro Iron. Again another investment piece but it's one of those things that you are going to love and wish that you had months and months slash years and years and years ago. The thing about the Aliso TG Pro Iron is that it has these little feet that automatically pop up out of the iron so that whenever you set it down it automatically lifts itself up off the table. What that means is no more of this hand motion. If your wrist is really weak or if you have arthritis or if your wrist gets really really tired after sewing and having to press so many seams, the TG Iron is going to save your life, I mean not literally, but it will make your experience in the sewing room so so so much better. Those little feet that lifted up off the table are like were invented by the owner of the company because his mom was complaining about having to lift the iron and how heavy it was especially when it's full of water. So he came up with this concept and now we have the Aliso Iron. In addition to the little feet that pop up though it is an exceptional iron all the way around. It's got a really like pointed tip to help you get into those like little nooks and crannies of your projects. The heat plate gets super hot and it's also super even so tip to heal you have an even heat and then it also sends out a ton of steam. You can control the steam with four different settings. You can control the heat too obviously but if you need a lot of steam it will send out a ton of steam. I have had my Aliso Iron for two going on three years now, still works perfectly, still works like a charm. I still love it. I don't have any leaking. The feet still operate perfectly. I have no issues with mine whatsoever. I absolutely love it. The coolest part about getting an Aliso Pro Iron now is that they just released some new colors. So I know it's a little bit of like a vanity thing but there are new fun colors that you can get that will add a little bit of fun and vibrancy to your sewing space. I have the pink one. I've had the pink one from the very beginning but the other colors are equally as beautiful and then as a little aside they also have a mini iron obviously less expensive just as powerful does not have the feet that raise it up. It's still really useful and really powerful tool to have in your sewing room and it's a little bit more or a little bit less expensive. So you can check out both of those options as well. So there you have it. That is my Mother's Day gift guide. Seven items that should be on your Mother's Day wish list. I have links for every single product and if there are coupon codes that I have that apply I will have those in the description box as well. I hope you all have the most amazing Mother's Day in that you are spoiled rotten whether it is with material things like the things I've gone over today or just with love and affection and attention and everything that you deserve on this day that celebrates you. So happy Mother's Day everyone. I'll be celebrating with my baby my fur baby that is. We are all mothers in one way or another and I just hope you have the best day but that is going to do it for me today. Thank you all so much for watching. Check the description box and I'll see you all very soon. Bye.


We know when disasters happen, usually most of the telecommunication infrastructure at the street, either naturally or purposely, and there is a need to restore at least a temporary equipment to help all the respondents communicate and to help the rest of the world know what is happening in that country. Telecommunication is part of its largest part of relief activities. And this is something you have to do not for one day or two days. Number one, you have to provide relief and then later on help restore, rehabilitate the infrastructure. And because of that, you need funds. And it's something you have to do consistently. And you have to make sure that the funds you have, it's a process that is sustainable. That's why the SSDM advisory board decided to set up a fund for that so that when disaster occurs, people are prepared in advance and then they can help provide some relief to disaster-stricken countries. There is a lot of money spent in that area to provide relief to disaster-stricken population or countries. But today it's dispersed, scattered. You have a food program having funds, spending. We have a well-banked spending fund, Billgate Foundation spending fund. So it's scattered. And we think that if it is well-organized and there is a fund, number one, we will need less money to do more than what we have been doing. And then it will be something we can do consistently. And it won't be only providing relief to country, but we can work on disaster preparedness, help people, you know, train people locally so that we have people, local people, who know how to address those situations when it happens. Not just waiting for people flying from outside in to provide relief. Number one, and then we can have in those, in all the countries actually, you know, because no country is immune to that. It could be natural disaster, it could be people provoke disasters, but no country is immune to that. So we can have in all the countries people prepare. First of all, and then we can educate people also how to address the first steps when it happens. So we think that, you know, it's something we can do and we just have to put in place a good value proposition, meaning explain to people we benefit from doing that. Because we do not only address ICT for the disaster management, it's also ICT for development. Because, you know, all the infrastructure used for normal development of country can be used when there is disaster. So we don't want to separate, you know, ICT for development to ICT for disaster management. There must be a bridge between, from our traditional network, you know, telecommunication network, that can be used also as a basis. You know, it depends on it. It can be used for disaster management. The problem now, we have to think differently how we conceive our networks. So we have to educate people so that we know that, you know, when you build your network, you have to provide for backup in case of, you know, disaster situations. And this is something we have to educate people to do. It won't take more money than they spend to build their network. It's just a matter of engineering, how to conceive, how to prepare their network. So this is something we have to do, definitely. And we think that if we do so, definitely we will be able and that's what we know the SSDM initiative is all about. It's ICT for development, bridging to ICT for disaster management.


All right. Good morning. Thanks for coming. So today I'm going to tell you how to get topology hiding computation on all graphs But first, let's talk a little bit about Facebook. Facebook is great It connects millions of people all over the world with their friends and families and co-authors Allows you to exchange messages Tell them how you're doing what you're doing your likes your dislikes as long as all of that information goes through Facebook in this model Facebook is a trusted third party and Using Facebook it can compute functions on your personal data and the the social graph of friends that you have at the price of Facebook knowing all of your personal data and all of your friends and this is for example why one of our co-authors doesn't use Facebook so What if we wanted to get a decentralized social network that way I could talk to one of my co-authors over Facebook now So in this model we no longer have a trusted third party and your friends can talk to you can talk to your friends your friends can Talk back to you and you get privacy both for your personal information and For the social graph so you don't need to reveal Who all your friends are to anyone else? Now you might be thinking wait we already have something that does this we get privacy for your data with Multi-party computations set it in the 80s and the setting is you have multiple parties each with their own private inputs Who jointly want to compute a function without revealing anything beyond the output of that function? however The setting for MPC has the communication top topology being public Meaning you're either dealing with a complete graph where every party can talk to every other party Or if you have an incomplete communication graph It's public and everyone knows who's talking to whom So MPC does nothing to hide any of the metadata of the computation that goes on and unfortunately Metadata is a very powerful tool as the former director of the NSA once said you can kill people based on metadata The idea is you can infer a lot from who's talking to whom And that leads us to our goal. We want to get topology hiding computation Topology hiding computation is a kind of multi-party computation that hides both the input and the communication graph It is good for this social network example There are many applications and another application is Maybe you have a vehicular network where when cars are close to each other they can communicate and Disperse information about traffic patterns hazards weather On the highway, but maybe you don't want to reveal where you are relative to other cars in this network So more formally the setting for topology hiding computation Yeah, each party has their own input for a function and parties can communicate directly only with their neighbors Our goal will be given minimal information about the graph maybe a bound on the diameter of the graph or the number of nodes We want to be able to compute any function on the inputs while revealing nothing beyond the output and this includes revealing no more information about the graph to formally define this like the security of this Model we say that an adversary who statically corrupt some set of nodes Can't tell if he's interacting with a real graph or if he's interacting with a simulated graph That so the simulator knows the output of the function and it knows the local topology of The adversarily corrupted nodes notice the simulator doesn't have an edge between nodes one and two Because he doesn't know that exists and node six isn't in the simulated graph because the adversary can't tell that that note exists Okay, this seems difficult is this even possible Well, it turns out instead of having to prove that we can get any function at all in this model It's enough to prove that we can get topology hiding broadcast So our goal is going to be to get broadcast So the setting is let's consider a naive broadcast to demonstrate this we have a broadcast node node two Here who's got a broadcast bit and wants to let everyone in the graph know the broadcast bit So in the first round nodes one and three get the broadcast bit in the next round One and three send the bit to their neighbors who get the broadcast bit and then finally Node six gets the broadcast bit from from her neighbors This is not topology hiding For the reason that it reveals the distance to the broadcaster as soon as One and three get their message in the first round They know their distance one from the broadcaster these guys know their distance two and node six knows She's distance three away So it turns out that this is even harder than we Than than that it's impossible to get topology hiding computation against any kind of the almost any kind of active adversary like Say your adversary just has the power to abort to stop communicating communication from through his node in 2015 Michelson showed that Against a fail stop adversary topology hiding broadcast is impossible and they did this just by showing that if you have an adversary like this middle adversary here who can Stop working and disconnect the graph then this reveals something about the topology of the graph However, the good news is we can get some results. We already have some results on against passive adversaries So in 2015 and 2016 There were results on getting topology hiding broadcast on small diameter graphs and then earlier this year a caveat Moran showed That you could get topology hiding broadcast on some large diameter graphs including chains cycles and trees But the question remained open is topology hiding computation possible for all graphs Well, I wouldn't be standing here If the answer wasn't yes It is and that brings us to our formal results So assuming that Decisional Diffie helmet is hard topology hiding broadcast is feasible for all graphs Explicitly our contribution. So the a Kevian Moran protocol showed that given DDH We can can get this thing called or homomorphic privately key commutative Optimizable encryption and then we show that this gets us topology hiding broadcast for all graphs Now let's focus in on this or part here so Or implies broadcasts. So we're instead of just going straight for broadcast. We're going to show actually how to compute The or of a bunch of bits on a graph So this works because the output bit is actually equal to the or of the output bit with a bunch of zeros Great. So the source node is going to have his output bit All other nodes are going to have zeros and if at the end of the computation everyone gets the or of the output bit You will have broadcasted that bit So our goal will be to compute that however Note that naive oring is not topology hiding that is if you you know Just try broadcasting your bit to your neighbors and then oring the bits you get in return You run into the same problem that you did with naive broadcast if the output bit is one you know exactly when you receive that output bit So we're going to need these these tools the first tool is we need our encryption scheme to be or homomorphic so you have Two encrypted bits and you need to be able to Homomorphically or them to get there to get the encryption of two of the or of those bits Moreover, we need to hide the number of times. We've ordered a one or a zero Even if you can decrypt the message you shouldn't be able to tell that is an encryption of a one Needs to look just like an encryption of a one or with a zero homomorphic Lee needs to look just like an encryption of a one Or with a one homomorphic Lee Turns out you can get this just using Algamol All right, this brings to mind the following construction What if we just tried the naive oring protocol, but now we encrypted our bits first and then Ored them as we went along well We run into the problem that this doesn't quite work because how do you decrypt at the end? You you run into the problem of who has the secret key? How do you get the secret key to everyone else in the graph? So we need one more Property for our encryption scheme And that is where this privately key commutative randomizable encryption comes in Notice I have a picture of an onion on the screen That is because we will be able to add layers of public keys and delete layers of public keys Okay, how do you add layers to an onion? Maybe it's more of a parfait. I Digress So when we add a layer, what do we what are we what are we doing? We have an encrypted message Under one public key and then we have a secret key that is unrelated So we have a message encrypted under the blue public key and a yellow secret key And using this we can add a yellow public key layer to our message this image might be a little bit misleading We're not re-encrypting in an already encrypted message We're actually multiplying the two public keys together So what this actually is doing is producing a message that looks like it's encrypted or actually is encrypted under the product of the two public keys Now when you delete a layer You're just doing this process in reverse you have your encrypted message that's Got this layered property and you have a secret key corresponding to one of those public keys and then you can just remove that layer Great, this is also possible using El Gamal So now that we have both of these two tools We're ready to go through a warm-up protocol before getting to our actual protocol for all graphs So I'm going to discuss the Akivia Moran protocol on getting or on cycle graphs So they're going to be two phases The first phase is a forward phase where we're going to add layers going one way around the graph The next phase is a backwards phase where we're going to remove layers Going back around the other way on the graph Let's focus on How node one is going to get the correct output bit so in round one node one is going to encrypt his bid and Then send it to node two No, too round two is going to generate a new public secret key pair add a layer homomorphic homomorphically or her own bit and then send this resulting message to node three No, three does the same thing a new public secret key pair Adds a layer or is his own bit homomorphically sends this to node four. All right. We get the idea. Hopefully No, four adds a layer or is this bit sends it to node five node five doesn't need to add another layer It just needs to homomorphically or his own bit And now we have encrypted up here the output bit And now we can begin the backwards phase and start going back around the graph Hopefully you see where this is going so node five sends this entire message back to node four node four uses the red secret key to remove the red layer Sends this back to node three node three uses a light blue secret key to remove that layer Sends it back to node two who removes a layer Sends it back to node one now node one has the corresponding secret key here. So node one decrypts the message and now has in plaintext the aura of all bits in the graph great Well, node one has the output, but we now need to make sure that every other node in the graph also gets the output bit This isn't too hard. We'll just run the same protocol Simultaneously for each node So Correctness of the protocol and run one everyone, you know sends their bit to their neighbors Run the protocol for every node every node is going to get the output bit at the end To argue topology hiding of this protocol First we have to know it that you know, everyone knows they're in a cycle So what are you hiding? You're hiding the order of the nodes in the cycle And you can see this Intuitively because of the semantic security of the encryption means you can't tell when you get a one or a zero and the Rewanimization the adding of the new public keys mean that each node's view is indistinguishable from any other nodes view Great. So our work is going to essentially extend this whole like adding layers and oaring protocol The Kevian Moran protocol had this observation that if you had a path that covered the graph Your protocol would be correct So instead of taking a prescribed path around the graph We're just going to take a random walk and as long as a random walk covers the graph will be fine We can hit the same node more than once This won't matter because oaring a bit twice is it isn't going to change the output at all and And as long as every node runs a random walk every node will get the output bit at the end So this brings the following protocol to mind every node is just going to start a random walk and By as long as it runs long enough every random walk will cover the graph and every node will get the output bit This will not be enough For the following reason so let's say let's focus on node three So let's say every one of nodes three's neighbors decides to start the random walk by sending a message to node three Node three being a diligent node is randomly independently going to decide where those walks are going to go next Well now we have a problem nodes two and seven have now learned that node three has another neighbor other than themselves Node four has learned that node three has two other neighbors and Node five has even learned something probabilistically about the number of neighbors node three has So this is also not topology hiding So to fix this if you look at the title of the slide we're going to use correlated random walks and we're going to Make sure that the graph topology doesn't affect how many messages go along each edge So we're going to have one walk per direction on each edge. This will be clear hopefully in a moment So to correlate the walks node three is going to get messages from all his neighbors walks from all of his neighbors And then he's going to generate a fresh random permutation and Then of his edges is going to permute those messages around to decide where to send them next and then he's going to send those out He gets one message in on each edge one message out and sends one message out on each of his edges and As long as you invert the permutations on the way back The protocol is still going to be correct Speaking of correctness. We have to make sure that the random walks don't actually take too long to do that We're going to talk about the cover time of a graph G The cover time of a graph is the maximum expected time it takes to visit all nodes in a graph using a random walk And we have this convenient upper bound 4n cubed on the cover time of any graph on end nodes So this means if we take about end of the four steps We will cover the any random walk will cover the graph with overwhelming probability And so we prove correctness for all of the random walks in our graph just with a union bound and So we have correctness of our algorithm. Let's finish with some security so Let's focus again on node 3 node 3 gets encrypted messages from its neighbors every round He can't tell if he's getting a 0 or 1 because of semantic security Because he's doing all of this permuting of the messages everyone else is doing permuting Rerandomization adding a public key He can't tell where any of those messages have been for example He can't tell if the message he got from node 7 came from 8 or from node 6 And this means node 3 can't tell if he's interacting with a real graph Or if a sim or with a simulator who only knows the output bit and the local information of node 3's neighbors so in the forward phase of the walks the simulator just Sends encryptions of 0 through 3 and in the backwards phase the simulator just sends encryptions of the output bit by the end of Protocol node 3 gets the output bit as expected Now to One one more fun little note here is that we can de-randomize the walks This is interesting because it brings us one step closer to getting a perfectly correct topology hiding algorithm I say one step because unfortunately We have negligible error both in the walks and in the homomorphically Secure encryption scheme the Algamol is has a negligible probability of failing so We have our universal explorer up here And we're going to be using something called a universal exploration sequence to de-randomize these walks a Universal exploration sequence is just a set for for graphs of size n is just a set of instructions Such that if you follow them for a walk you're guaranteed to hit every node in the graph Any graph of size n and the best part about these walks is that they're all relative to position and locally computable So every node in the graph can compute the same set of Instructions the same universal exploration sequence All right, I'm going to conclude with a couple of open questions So it is impossible to get topology hiding computation if the adversary can disconnect the graph But what if we don't allow the adversary to disconnect the graph But we still will let him deviate from the protocol in some way then there's also the question of Dynamic graphs in the example where you have cars on a highway communicating locally with each other You always have cars entering the highway and leaving the highway So the graph is going to be changing but not adversarial II And finally here is a slide reviewing the algorithm Thank you


NCSSM Online is an absolutely amazing program. It is an experience in itself that you cannot obtain anywhere else. It's probably the best course you'll ever take during your high school career. It's actually a lot of hands-on approach, even though it is an online program. This isn't exactly what I thought it was going to be. This is a lot more. NCSSM Online is a unique, tuition-free program of online learning blended with real-time relationships and on-site residential activities. This exceptional two-year hybrid learning experience gives students a unique blend of connections. Using state-of-the-art technology and a dynamic online learning environment, this program is greatly enhanced by featuring a residential summer experience, as well as on-campus weekends throughout the school year. These residential weekends provide time for collaborative classroom work, labs, field trips, and the kind of bonding that creates a real sense of community. Our residential weekends here at NCSSM are comprised of several different aspects. The first one is that the students socialize with each other. They get to know each other better. They have time together so that they get more of that residential experience. The second thing is that we teachers can work with hands-on types of activities with them. I come from a very small school, a very small town, so we don't have a lot of fancy equipment and you limit it on the type of experiments that you can do, so coming down here is definitely really cool. The residential weekends are by far the funnest part of the program. You get to come here and meet these people who normally would just be like a name on a buddy list, but then you actually get to put a face to the name. Sometimes you can even call people, I text people regularly that I know from my online classes. We're just more comfortable with each other and it kind of eliminates the awkwardness because we're more used to each other and we kind of got a sense of each other's personalities. You learn just more about them than just sitting there and reading what they type. Designed to expand the NCSSM academic experience beyond the boundaries of the Durham campus, this innovative online program offers a host of rigorous honors or college level courses. These specialized courses are taught by experienced NCSSM faculty and feature the same challenging curriculum offered in the NCSSM residential program. The courses we're taking are exceptional. They're difficult, they're stimulating. There's courses that you don't really have much of an opportunity to take many other places. There are so many different components of chemistry and biology and so here you get to learn like focus on one component of biology and learn about that and understand it more deeply. Through NCSSM online, I really have the best of two different worlds. I can have these amazing courses and I can still have my music, marching band, research, friends. Well, it's really exciting because we're able to reach so many students that we could never reach before just through our residential program. For a student to be admitted to the NCSSM online program, they are screened very competitively. One of the essential parts of our screening process is to try to assess whether a student will do well in an online program. My students are doing very well in AP Chemistry online. I would say because I also teach a residential class, they're doing at least equally as well as students in a residential class and with some of them actually better. They really are being asked to be very responsible. I know especially it's come down to sometimes do I go see and move with my friends on this night? Do I stay at home and get some of my homework done, get my readings done? And I feel that it really gives you a valuable experience knowing how to decide what to do with your time, how to manage it well. These skills are definitely something you're going to be using for many, many years to come. An online course will help you prepare for college because it's not like a teacher saying do this now, do this now, get this done by now. It's actually you determining whether or not you want to put an effort to it. The innovative use of technology and communication tools creates a seamless learning environment. All course materials including videos, animations, graphics and text are contained within a learning management system. It's just easy and you can access all of it from one place instead of having to look something up and then go to a different site and email that and do this. Teachers keep up by seeing in real time when students are logged on to the system and what assignments are being worked on. Web-based video conferencing software is used at least once a week to ensure vital synchronous connectivity between teacher and student. It's really cool actually, I like using it a lot because there are three different forms of communication which makes it even more effective. Your teacher can talk to you, you can talk to your teacher and the whole class is there. There's an interactive whiteboard so like the teacher can work out a problem there in front of you and you can work out the problem also. You have an ability to raise your hand online and there's a modicon so you can say I'm smiling or I'm frowning or I'm totally confused. This is the way a lot of education will be taking place in the near future and so I feel like a pioneer and I know the students feel that same way as well. For me the NCSSM online experience was a way for me to rise to the occasion and you actually apply yourself to things outside of what you're required to do. The NCSSM online experience pushes you to reach your full potential. It's definitely not something that I had to do but it was something that I wanted to do. It's accepting the greater challenge.