The next talk will be given by Leonid Evdokimov, and he will be talking about Russia vs. Telegram technical notes on the battle, the stages to yours. Thank you. I'm greeting all the creatures in this hall, in the cyberspace and those who are in the future compared to me saying these words. My name is Leonid Evdokimov, and affiliations that matter for this talk are basically following. First, I love Internet protocol, and I love measuring networks based on Internet protocol. Second, I am not a Telegram team member, so no insights. Third, I was a happy Telegram user, and when the blocking started, I was extremely disappointed. Basically, I was disappointed enough to do something. But before describing the Telegram incident, I want to give a brief overview of Russian Internet censorship landscape. It will give some important context that may help you to prevent some erratic conclusions. First, attempts to filter Russian Internet segment is not a recent development. There were some activities in that area for, like, last 11 years. The first documented incident of Internet censorship in Russia happened in May of 2007. Court ordered four ISPs in Novosibirsk academic campus, also known as Akadem Gorodok, to ban some extremist websites. Those were small Internet service providers, so only small fraction of users was affected, and the incident hasn't made a loud news story. The registry that was used to block content in these ages was named federal list of extremist materials, but the registry was quite badly maintained. For example, one of the entries in that registry is exactly the following. Text document named terrorism from the folder named orders number one, CD disk number one. That's it. That's the entry of the registry. So the list wasn't very useful for the purpose of automatic content blocking. One of the notable events of that era is the act of digital resistance by Maxim Mashkov. Maxim is a cyber librarian of the oldest Russian Internet library named Libru. One of the sections of the library is named samizdat, that basically stands for self-publishing in Russian. And that samizdat journal hosted user-generated content. Once the domain of the journal was added to the federal list of extremist materials. Of course, that wasn't a surprise, because also people know that samizdat is kind of really extreme civil disobedience. Maxim decided to bring some fun or fairness to that case, and he transferred the useless domain to the ministry. So basically, he pointed the domain of the samizdat library to the website of the ministry of justice. As expected, that eventually caused some incessibility of meanjust.ru. The modern blacklist, as we know it, appeared in 2012. The law was brought to protect children of all ages from one or zero to 100 years old, from digital drugs, from child porn, and from various safety guidelines, also known as suicide how-tos. The major websites protested, but the parliament didn't care that much, and eventually the president have signed the law on Saturday. Now I know that president works on Saturdays. So how does modern earth comminator blocklist look like? It's an XML file signed with detached signature using ghost cryptography. Also, the bundle of XML file and the signature, it is wrapped up in another XML, as the file is fetched using SOAP protocol. The protocol documentation is publicly available, as well as the API endpoints for testing. The essence that you should know is that internet service providers actually control the filter and equipment they purchase. It only maintains the blacklist and monitors that filters of internet service providers actually work. So, when the blocklist first appeared in November 2012, it immediately delivered a lot of fun to us. For example, it blocked absurdopedia, basically Russian version of unsyclopedia, and exactly for suicide how-to. Of course, the grotesque of blocking of humor's content got some media attention, and some brave creature decided to link the blocklist to GitHub to codify that absurd for ages. So, two weeks later, after the first blocklist to release, GitHub and Sourceforge got a copy of the blocklist, and that copy was kept up-to-date for years. It still kept up-to-date, and it still maintained. I don't know anyone who knows the person maintaining that blocklist mirror, so the stock is basically the only way for me to thank that maintainer for all the work he was doing during the last six years. And, of course, another fun incident in the same month, like within a few weeks, some of Google services were also banned for a day or so. So, anyway, who needs jQuery libraries from jstatic.com? And I can spend the whole time slot of the talk describing funny incidents regarding the blocklist, but it's not the main topic today. But I can't resist, so I'll just name a few more. First, the Pornhub. It was a pioneer that used legal procedure to unblock the website that was blocked previously, and that legal fight, it deserves some Second, Roskomnadzor obviously loves TCP dump, for sure. That's, you know, the only sane way to explain how certificate authority or revocation lists and OCSP responders of KomodoCA were banned. And that CI ban, it caused some quite solid collateral damage and hard to debug problems. Third, Roskomnadzor either have some sense of humor or just lack sanity checks in the blocklist maintenance procedures, so it really banned Lubeck address for a while. As I've earlier said, Roskomnadzor monitors that ISPs actually implement filters. The reason for monitoring is understandable. The law doesn't matter. The fine and the penalty does. So, ISPs got some new year gifts in 2016. That was a tiny open VRT router based on TP-Link platform. Wildex, well-known Russian hacker, has hacked the firmware and highlighted some really nice facts in his research. First, API of the command and control center of those measurement platform, it was reached over HTTPS. Sounds good so far, but unfortunately, CA certificate bundle was absent, probably due to image size constraints. Also, SSH was used to do some reverse tunneling. That sounds like a usual and good idea to penetrate networks address translation as soon as IPv4 is still widely used and the modern IP is not that much, at least in Russia. But server, host K check, it was absent. So, it was basically disabled. That allowed Wildex to inject some nice screenshot of cyber garbage into Roskomnadzor monitoring pipeline, at least according to his publication. If his prank succeeded, that was the picture that Sensor was seeing in the back office while checking the screenshot of the website that had to be banned. The real issue with the Revisor monitoring system is that it is a black box, at least from ISP's standpoint. It's not publicly documented. What sort of behavior the black box has, what sort of filter is good enough, and what sort of filter leads to fines. Eventually, one of maintainers of Revisor system, the governmental employee, has written a public frequently asked questions for Revisor on GitHub to help ISPs to comply, and he claims that it reduced overall amount of fines. This sounds like good activity, but before that, some ISPs had to put that monitoring system, Revisor, into a strict sandbox that had way more tight filters that ordinary users were expecting. And, moreover, the sandbox solution was so widely discussed and so popular that it became the logo of semi-official telegram channel that discussed Revisor-related issues between ISPs and governmental employees. As soon as ISPs were first to comply with the black box, as soon as XML file contained stale IP addresses of their websites to block, as soon as the black box was actually using IP addresses from DNS to check for compliance, because all of that, some ISPs started to feed A and 4A records stride from DNS to their filters. And, of course, it was prone to some malicious manipulations by domain name owners. Though manipulations were called DNS attacks, and there were various sources of them. Some of ISPs used IP addresses from DNS to actually block traffic, that's boring, but those ISPs have brought their users some collateral damage, when domain names were pointed to IP addresses of good services. Other ISPs used IP addresses to steer some portion of traffic towards DPI boxes to reduce overall amount of bandwidth going through DPI. That's very smart and it saves some electricity, so it's kind of green, but unfortunately it may lead to most specific routes overriding ordinary routing rules, when domain names were pointing to IP addresses of peering subnets. Or, in the worst case, routers can just go on strike, when blacklisted domain names are pointed to something like million and a half of distinct IP addresses, and basically overflow routers to come memory. As you can guess, all those incidents have already happened, so no news here. I'm sorry if the history section took too long, but some faults deserved highlighting as they are quite universal across different filtering systems. So the story of incident with Telegram starts here, basically when Policeman enters the game. So what's the essence of the reasons to block Telegram? It's quite easy to understand. Terrorists who float the bomb in St. Petersburg subway, they use Telegram. Also, every ISP member enjoys slick UI, nice stickers, and videos in circles, according to news and Russian satirical videos. Some people also name popularity of Telegram in opposition groups as a reason for ban, but discussing the reason of ban is out of the scope of the talk anyway. So it's easy. Telegram is added to the registry of information distributors, so it has to comply with the law, and it has to do some decryption, magic, basically to help police, and otherwise it will be blocked. So when the Telegram was duly added to the registry in the classified location, it claimed that it will never hand over keys or do backdoors. So Digital Rights NGO started a campaign for encryption and stuff. And eventually the court cases were lost, at least in Russian courts. The case was escalated further, but it's born legal stuff. So the key point is, on the 6th of April, Roskomnadzor started to block Telegram, and following few weeks were named the first Russian civil cyber war. But let me give me a bit more context. Telegram wasn't the first messenger that terrorists love. Zelo was another one. Zelo was also used by protesting truck drivers in Russia, but maybe those drivers were meant to be the terrorists. Who knows? Anyway, once again, out of the scope. So attempts to block Zelo were ongoing since April 2017, and they weren't a complete success. And there was a leak in the end of March 2018 saying that Roskomnadzor plans to conduct an experiment to test new tactics regarding blocking of Zelo. The leak paper, it had 36 subnets summing down to something like 15 millions of IP addresses of Amazon and other cloud providers. And the leak had like nice keywords like null routing, BGP, redistribute. You all know that you have already seen it before. So I'm unsure what they actually meant with that experiment. And I don't know if the leak was genuine, but that publication of the leak caused a lot of noise in the media. And there were no further reports that could confirm of existence of a like experiment. So maybe media worked. Moreover, some illustrators drew really good pictures that could clearly communicate the overall Roskomnadzor plan regarding attempts to ban Zelo to every, I don't know, to no technical granny, for example. So back to Telegram. On Monday, April 16, Roskomnadzor starts to ban Telegram subnets. Some of Telegram subnets. As expected, no sign it can affect all the nodes. So Roskomnadzor went berserk and started banning Amazon. But Telegram worked. Finally, Roskomnadzor noticed that one of Telegram subnets wasn't banned initially yet. And of course, that didn't help them much to achieve the goal when they banned it. So berserk mode wasn't turned off. And almost two million of IP addresses were banned by the end of the day. Telegram was doing fine, but overall internet wasn't. I mean, like, from Russia. Internet was okay. But people in Russia were complaining a lot about Instagram, about Steam, about World of Tanks, World of Ships, Twitch, YouTube, Google, Gmail, and so on. So basically, everyone was swearing at Roskomnadzor by the end of the first day of civil cyber war. But actually, everyone stopped swearing the next day when the amount of banned IP addresses increased tenfold. Everyone was just speechless. There were no good swear words to express amount of frustration. And every other online tool was broken, basically. Millions of domains were affected. And in the meantime, Roskomnadzor was announcing that no socially significant web services were affected. Of course, I don't blame Roskomnadzor for mistakes in their announcements, like employees implementing the ban were obviously very, very tired and stressed while rushing to shut down Telegram. And they were in such a rush that they have banned several IP ranges twice. Submitting overlapping subnets into digitally signed a blog list on the second day of the civil cyber war on the 17th of April. And probably the equipment could handle that, the filters. But some people counting public statistics for the blog list, they got their numbers wrong because of that. But if the NSE checks are missing, they are missing everywhere. So some malformed URLs were added to the blog list as well during the incident. And the malformed URL, it actually caused some filter implementations to fail ingestion of new blog list entries, new blog list subnets and new blog list IP addresses. But I think that it probably was just a mistake. I don't expect that it was carefully planned sabotage of some Roskomnadzor employee. During the first days of cyber war, Roskomnadzor has distributed a document with some white list of socially significant services, including Google, by the way. That included websites also like Kremlin rule. Those shouldn't be banned under any circumstances. Probably that was a response to numerous reports regarding collateral damage. But unfortunately, Roskomnadzor had no legal framework for like actions. So many ISPs just ignored the document. But it caused some media wave as soon as the white list coming from censorship agency was something new for Russia that day. Anyway, the mantra regarding socially significant services was repeated over and over again. But like counter of Yandex metric or Yandex banner system endpoints were banned in the midnight of April the 27th. And VKontakte was also banned by same commit. And VKontakte is the most popular social network in Russia. So the incident last for almost two hours. And it clearly showed that, first, Roskomnadzor works selflessly around the clock. Second, Roskomnadzor still loves to speed up and still loves to feed IP addresses right into the black list without much analysis, as it previously happened with KomodoCA. In addition to generic mantras regarding socially significant websites, Roskomnadzor was spreading quite precise statements in their news feed as well. One of the statements claimed that IP addresses of Google Play, Google Drive, Google.ru were not banned. Of course, we, Azure 2 Club, sorry, were very happy to hear that. The reason is crystal clear. Precise statements are refutable. And it's always fun to refute official news coming from official news source in fake news era. So we scraped hundreds of IPs of various Google domains sending different client subnets to Google's name servers, checked, collected IPs against black list.  And it was kind of interesting that there was more than one cluster of interconnected Google domains pointing to same IPs. Probably that makes some sense from traffic engineering perspective, but it also explains the reason for some Google fonts and points being unreachable while others were perfectly okay. But it wasn't the only fun visualization we made. On April the 19th, we took the ripetless probes in Russia that absurd filtering pointing them to randomly selected TLS endpoints in filtered subnets and crafted live Vekomo dashboard. That dashboard showed that some ISPs are basically practicing digital resistance. The reason to create like dashboard was clear for me. I didn't want for huge ISPs, those are too big to fail, to use the possibility of noncompliance as a competitive advantage against smaller independent ISPs who can't take the risk of paying fines. But members of ISP community asked us to hide the dashboard within something like half an hour. For the reason I still don't quite understand. And anyway, noncompliance story still goes on. At least for Rostelecom, the largest ISP that holds like one third of a B2C broadband market share. Experiments have shown that Rostelecom doesn't block traffic to blacklisted IPs and subnets completely. It blocks just HTTP and HTTPS traffic. And for example, SSH works perfectly. And once again, that state-owned ISP holding one third of a market, you know, like here is an example of noncompliance or basically delayed compliance I'm speaking about. The blocking, blue dots close to zero, it was delayed by something like five days while they have to implement the blocking basically as soon as possible or within 24 hours depending on various variables in the XML file. So like unblocking was perfectly timely. As the civil cyber work continues, people use proxies and tor to assess telegram. And they get indicated. And artists craft party songs about proxies, they mock Rostkom-Nazor and people have a great share of fun. But Rostkom-Nazor hunts proxies as well as telegram. And people wonder how they do it. Some people start suspecting that lawful interception equipment, also known as sorm, is used to hunt proxies. And tips come via public and private channels, highlighting instances of like sniffers. Basically, the instances were exposing traffic statistics publicly. And the traffic statistics also had a section of telegram traffic that attracts the attention of people who send us some tips. With correct statistics page, and it turned out that all those instances were pumping quite small amount of traffic, something like 20 gigabits per second. But the shape of traffic looked like real one. We looked up those instances using Shodan and we have seen that some instances had public FTP repositories with sorm binaries basically. And what was significantly worse, some instances were leaking actual users' clickstream and some personal information like mark addresses or logins. And of course, all the data was available without any authentication. So, being good citizens, we decided to report the incident to the vendor of sorm equipment and ISPs hosting the lawful interception equipment. I got no replies, but some instances were properly secured within the next few weeks. But some weren't. Anyway, we concluded that the tips we got, they had no public evidence that sorm equipment was actually used to hunt telegram and proxies. At least statistical counters about telegram, they were zero because, you know, subnets are blocked. But you also know that absence of evidence is not evidence of absence. Another telegram story that is kind of interesting is that the protest meetings happened when the app was blocked. As far as I know, it is the very first time in Russia when protest meetings are triggered by blocking offline service. The meeting was scheduled on the last day of April and the first day of May in Moscow in St. Petersburg. On the 28th, the Saturday before the meeting, number of blocked IP addresses went down from 90 million to 15. So, it's unclear if the action is caused by the activity of the society, but maybe it's just a coincidence. I don't know. But we assumed that media attention may help to reduce collateral damage caused by massive subnet blocking.  I have previously described DNS attacks that caused a major outage of trans-telecom internet service provider. And one of the outcomes of that incident was a chart that was monitoring the account of IP addresses that are appointed by blacklisted DNS entries. Basically, if the chart skyrockets, it may be an indicator that ongoing DNS attack. I have previously registered some expired blacklisted domains for network measurements to present the results of those measurements at the round table of the parliament. And those domains were still alive. So, I took some of them and added some dynamic DNS zone script. And the script was updating the zone, so nice Moore's code appeared on the chart. And the plotted phrase was like digital resistance. Unfortunately, it hadn't triggered any visible actions from Roscomne. But another reason that could explain that is what the performance could be linked to Alexey Navalny's opposition meeting. They had some protest on the 5th of May. So, we took that as a hypothesis and continued. First, some cheap drama was added. The chart was doing countdown from 5 to 0. And it was doing it very slowly. And fake drama kind of worked. The countdown has triggered some nervousness. And the message was as friendly as possible. Russia celebrates radio day on the 7th of May. That's a professional holiday for all the people involved in telecommunication. And the message was truly pop-off. That is a well-known celebration greeting for that holiday that basically follows Pascal greeting pattern. And that message, it had some effect. Roscomne started to clean up domains from the block list while the end of transmission chart was plowed. It caused some nice fade out. But also, Roscomne has banned and unbanned, like, unperceived TLD. Maybe it was a sign of unity on solidarity, I don't know. And second, amount of banned AP address dropped significantly. Third, Roscomne started to remove expired domains from the registry, reducing possible impact of various DNS attacks. So, it was maybe a hype-driven cleanup, but the proper expired domains' maintenance persisted. And it was good for overall network stability. Maybe it was a coincidence, I don't know. Another unblocking happened on the 8th of June, and anyway, all those cleanups were followed by people computing the statistics of IP addresses over remaining banned after subnet unbanned. And the number was less than 1%. And so, some people were saying that Roscomne Azor was using terrorist tactics while fighting with terrorists using telegram, basically taking those networks as hostages. I had an assumption that leftovers of collateral damage could be also explained by something like incompetence or lack of big players in those subnets. So, I've spent days mining open data on DNS, reading an open letter to Roscomne Azor, giving off overview of blocked web resources, like Slack, GTC, PowerDNS, Doodle, Python, mailing list, Netlify, and so on and so forth. And American Niguelist Underground Society, anus.com. And the letter was also due to corresponding legal online form of Roscomne Azor. Someone survived, but it was like pointless legal speak. So, maybe those networks are really hostages, I don't know. So, that was a brief story of heated part of the civil cyber war. But the cyber war wasn't over. It became colder. One of the observations we made was a selective protocol throttling. Telegram clients picked several protocols to the proxy. Sox5 and variations of telegram-specific look-like-nothing anti-proto protocol. And I discovered that one of major mobile broadband ISPs doesn't treat those protocols equally. At first, I assumed that all look-like-nothing protocols were shaped as OVS4 plug-able transport and bare net-cut U-random. They were tripled as well. But thanks to Simone Basso, we conducted an experiment and confirmed that it's not the case that HTTP protocol that is stored with RC4-random stream, it was also absolutely okay. It's unclear if the shaper is targeting specifically anti-proto or like some other protocol, but it's definitely more complex than I originally assumed. But it also means that camouflage matters a lot while designing plug-able transport. Another proxy availability issue was observed in one of the first telecom subnets in South Russia. Anti-proto proxies operating without random padding were banned almost instantly. And it was trivial to trigger DPI equipment into resetting the TCP stream, just sending the packets to the listening TCP port. But there was a thing that was really bad in that setup. The IP and port of the network endpoint were added to dynamic block list at the DPI box for a couple of hours. And we assumed that the vulnerability that was created by that, it could be possibly exploited even from the JavaScript from browsers to ban good web resources, basically. So we decided to disclose that shady practice immediately instead of researching it further. And there was a Reuters news article a couple of months later that kind of confirmed that like experiments on live traffic were actually happening. It's unclear to me if like experiments are legal, but some people consider that it's like crying. Another proxy service availability issue was observed in Moscow, thanks to St. Petersburg city FTM. They dissected the story. First, the user connects to SOX5 server, then a map scanner comes in something like half an hour. And if a port is available, like the scanner tries to establish a SOX5 connection to telegram cloud. And if all the checks are okay, then IP address becomes blacklisted. The story has attracted some non-zero media attention from local international media. But the most interesting part of the story was left unnoticed. The only reason for me to replicate the study in Moscow subway was the ability to manipulate the block test and add the IP addresses of my own servers to it. It allowed me to conduct an experiment that I consider extremely important. We were able to measure the timeline of block list rollout using diverse set of right palace props. And statistics we got was very interesting. It allowed us to verify the tip that we got in May. And the tip was basically saying that there are actually two tiers of ISPs with regards of timing of block list execution. So there are ISPs that start blocking IP address before officially signed XML block list is delivered with API. My personal opinion is that it's not necessary crime. There are other sources of blacklisted endpoints. For example, federal list of extremist materials. Also, digital security lab Ukraine reported that Crimea has both regional blacklist and federal blacklist. But I know nothing on that region. Go ask Xenia, who may be in this room as well. And also, there were like tips coming from Caucasus regarding like stuff. But the thing that you know for sure with high level of confidence is that some regional governmental Internet blackout happened in Dengushetia this autumn during protest. Another thing we know that the race between ISPs to block is still persists. Anyway, Russia is federation. And that's almost it. As you may already know, whole Russian history can be summed up into five words. And then things got worse. And there was a law introduced to the parliament two weeks ago. The law says that Roskomnadzor will give some ISPs anti-treat equipment for free. And that the chosen ISPs must comply and employ it. They can't refuse that new year gift. And that anti-treat equipment will be acting as filter as well. As soon as ISPs deploying the anti-treat filter, don't have to buy their own filters. And there is a thing that is scary to me. The note says that Roskomnadzor will be able to control basically routing and DNS directly. And it's scary twice. First, we have already seen the level of technical competence and lack of safety checks and safeguards. I mean all the aforementioned mistakes. And second, it's huge centralization of controlling power that can be abused without any transparency. I assume that the luxury of signed XML blacklist will be gone soon. The law also introduced a registry of legal internet exchanges and lists of legal cables crossing the border to make absolutely sure that Russia is well connected. So it goes. I'd like to thank lots of people and groups who made this talk possible. Philip Kulin, Waldix, Michael Klimeroff, Dmitry Nazarov, Alex Rudenko, Dmitry Bilevsky, Vartanka Cheturov, Dmitry Moskin, Dmitry Morozovsky, Simon Basso, Maria Xeno, Moritz Bratl, Likta Blacklist, Maintainer, St. Petersburg CTF team, Roskomso Bode NGO, Digital Resistance Measurement Squadron, the one who is to blame all the revisor system fans, the NAG community, Rye Patlas, and all the relatives and colleagues who helped me to survive while doing all the stuff sometimes quite narrowly and round the clock. And of course, I'd like to thank Stubbornness of Pavel Durov and Law Enforcement Bodies because that fight made all the great entertainment possible. And I hope the story was entertaining as you as well. Thank you. Thank you, Leonid for the excellent talk. We have five minutes left for questions. So if you have any questions, come up to the microphones that are standing in the aisle and to the left and the right and wait for my signal. Microphone one, please. Hi. Thanks for a talk. During the whole blocking situation, I heard that Telegram continued working in Russia. Do you know if it works right now? Yeah, it works perfectly. Like, there are some ISPs that are maybe over-compliant and it works a bit less good there, but Proxy's work, Telegram works. For example, like Ross Telecom, as I have previously mentioned, doesn't comply with subnets and Telegram works flawlessly there. We also have a question from the Internet. Signal Angel, please. Yes. Somebody is saying on the Internet that Telegram had a canary statement on their privacy page, stating that no data had been disclosed to any third parties, including governments, and they say the statement has disappeared. Are you aware of that and what do you think about that? I'm first. I'm not aware of that. And second, I think that is like not a real, like, I don't think that we should be paranoid regarding that because my expectation is that it's just another mistake because like, Telegram team had like, I don't know, they write some questionable parts of the software. For example, Telegram client has no proper exponential back off and it can basically DDoS proxy in case of some DPI configurations. So I don't know. I think it was just a mistake by Telegram webmaster. But maybe it's not. I don't know. Anyway, I'm not part of the team. Microphone 4, please. If you're worried by the lack of competency, should you work for the Russian government? I don't know. Maybe. Anyway, I still live in Russia. Like, there are lots of useful people there. And like, I don't know, I don't think that it is the worst government we had during the last century. So things are, sometimes they get worse, sometimes they get better. And I'm not sure where we actually are. But some of my friends are paranoid and they basically seek for political asylum. Some of my friends are quite happy to live in Russia. I don't know. Number six over there, please. Yeah, hello, Leonid. Thanks for your amazing talk. I really enjoyed it. I'm just asking. We, as a German people, can we rent your expertise when we get some problems like serious parking over here in central Europe? Is it possible? Well, like, the main point for my talk was not to complain about Roskomnozor, but basically to highlight the cases when things can go wrong because of Internet filters. And so that was the point. I'm not 100% sure if it, like, completely answers your question, but I think it does. And microphone two, please. Why do you think China is more successful in censoring the Internet than Russia? So the question is why China is more successful regarding censoring the Internet. I'm not sure that China actually is technically more successful in Internet censorship. Maybe it is, but the really important point is that there are a lot of Chinese people speaking Chinese language and they have a huge ecosystem of Chinese Internet that serves the purpose of basically a billion of people. Russia is 10 times smaller. It's significantly smaller market. We have some great local content, but amount of local content can't be compared to China. So maybe Chinese people don't need to circumvent censorship that much. And maybe that's why China is seen as more successful. And, like, friends of mine works with Chinese factories. And like, while they are traveling to China, they say that circumvention is not a problem. Like, everyone who wants to circumvent the filtering in China, he does it trivially. I don't know. I don't travel to China. But I trust those who do. Microphone one, please. Eileen, thank you for your interesting work. One question for me would be, did you face any problems through this work with authorities or services that somehow feel offended or attacked? I wouldn't say attacked. Like, I have some FSB officers in my WhatsApp phone book who were, like, talking to me, asking to educate them on, basically to give them a lecture on, like, Tor network or something like that. And it wasn't, like, offensive at all. Like, they were friendly. And why not? I think that education of law enforcement is really important because, like, law enforcement is doing not only, like, I don't know, oppression, but also a lot of dirty work that has to be done somehow. And I don't know. So far, I'm okay. Maybe I'll overcome the line eventually, but I don't know. One final question. Microphone four, please. Hi, Leneed. And thank you for the talk very much. I heard a popular opinion that after this talk, it's better for you not to come back in Russia. Sorry? Can you repeat, please? It's better for you not to come back to Russia after your talk here. Well, there is such an opinion. And, like, when I was doing that prank with Morzakot, I got a message from a person from Roskomnadsor using Telegram that said that I shouldn't come back. And I was basically coming back from Belarus to Russia. And I don't know. No one had met me. I don't know. We'll see. I'm quite optimistic. Let's thank the courage of Leonid again. And thank you for your excellent talk.


So let us now look at the asymptotes of the Hugoniot, so we could show that the asymptotes in the way we actually try to find out the asymptotes of this Hugoniot curve is to substitute that 1 over rho infinity goes to infinity and then find out what is the value of P infinity for 1 over rho infinity going to infinity to get this asymptote for you to get this asymptote you now substitute P infinity is equal to infinity in the Hugoniot relation and then try to find out what is the value of 1 over rho infinity right, so can be shown to be that means you show as in like you can do this is an exercise and it can be like a typical quiz question or an exam problem 1 over rho infinity equals 1 over rho not times gamma minus 1 divided by gamma plus 1 and P infinity equals minus P not minus P not gamma minus 1 divided by gamma plus 1. Now notice that gamma is ratio of specific heats which is greater than 1, so let us suppose it is about 1.250 something like that, so this is going to be like point something divided by 2 points something, so gamma minus 1 divided by gamma plus 1 is going to be always less than 1 and so 1 over rho infinity is always going to be less than 1 over rho not and therefore your asymptote is going to be to the left of the origin and similarly gamma minus 1 divided by gamma plus 1 again is less than 1 and it is going to be a fraction of P not that means it is going to be less than the less than the value of value at the origin but with a negative sign right, so it is now going to the other side and obviously that is not possible right, so this is less than 0 not possible not physically possible right, so the practical range of P infinity is 0 less than P infinity less than infinity it can go up to infinity that is possible, so where what is the range of rho infinity that is now going to span between where the Higonew intersects, so let us suppose that is how it is intersecting, so then that goes asymptotically to the lower bound there which is impossible but P infinity equal to 0 is about where you can go up to 1 over rho infinity you cannot go below this because P infinity cannot become negative right, therefore this is like your uppermost value of 1 over rho infinity, so you can try to find that out by plugging in P infinity equal to 0 in the Rankine-Hugonew relation right and then try to solve for 1 over rho infinity and get an expression. The lowest value is when P infinity becomes infinity, so that is corresponding to this particular value itself there of the asymptote right, so the range of 1 over rho infinity is 1 over rho 0 ?-1 divided by ? plus 1 which is what we have for the asymptote we saw just a little earlier and you are not going to really touch it because it is an asymptote and therefore you are not going to really touch P infinity equals infinity, so you are always less than that and so 1 over rho infinity is always greater than this not really greater than or equal to but you can go up to greater than or equal to what is now called 2Q divided by P0 plus ?-1 divided by ? plus 1 I am sorry this is ? plus 1 divided by ?-1 1 over rho 0. Now notice that this is actually dependent on Q that means if your Q is larger the Hugonew shifts to the right and top and therefore the point at point where it intersects the P infinity equal to 0 axis shifts further and further out right, so sure enough as you increase your Q this term is going to linearly increase right, so this is a range now what we also noticed was notice that the first quadrant of the Hugonew plot is not possible because Rayleigh line has a negative slope, so this divides the Hugonew into two parts the upper branch and the lower branch, so it can now begin to see what those limits are for each of these branches, so the Hugonew curve is divided into two branches the lower and the upper right, so along the upper branch the ranges the ranges are P0 P0 plus ?-1 Q rho 0 less than or equal to P infinity less than infinity that is going from here that is going from here all the way up to infinity right, so what we are actually locating this is P0 plus ?-1 Q rho 0, so as Q increases this curve is going to go up, so the point where this intersection happens is going to go up right, so P infinity then the lowest value of P infinity will keep moving up as Q increases, so this can obviously be obtained by plugging in 1 over rho infinity is equal to 1 over rho 0 in your Rankine-Hugonew relation right, so each of these expressions can actually be derived by plugging different things in the Rankine-Hugonew relation okay, the question is for what do you need to plug what is something that you have to think about and use your mind and you can get these expressions but these are like little problems that you can face in your exams, this is like a fertile ground for asking lots of little questions right, just to basically just your algebraic skills not really combustion skills okay, then this is as far as the P infinity is concerned and of course the lowest value of rho 0 so you can rho infinity I am sorry 1 over rho infinity that you can get is the asymptote and the highest value is 1 over rho 0 itself that is very easy for you to figure out right, so again we can write 1 over rho 0 gamma-1 divided by gamma-1 less than 1 over rho infinity less than or equal to 1 over rho 0 that is the range for the 1 over rho infinity along the upper branch along the lower branch the ranges are the ranges are again if you are now looking at P infinity it is going to go from here that is the highest value is P0 and the lowest value is this right which is 0 therefore so it is going to go from 0 less than or equal to P infinity less than or equal to P0 okay. And the you now look at the lower branch it starts from here so the lowest value of 1 over rho infinity is corresponding to this value which is obtained by plugging P infinity equal to P0 right so if you now plug P infinity equal to P0 in the rank and you go in your relation you should now get an expression that we should now be able to see readily depends on Q linearly so 1 over rho 0 plus gamma-1 divided by gamma Q divided by P0 less than or equal to 1 over rho infinity less than or equal to that is the other end where the P infinity becomes 0 this is something that we have already figured out that is this value right. So that is 2 Q divided by P0 plus 1 over rho 0 gamma plus 1 divided by gamma-1 good so these are these are just algebraic expressions that you can get for the different limits for the upper branch the lower branch separately okay now as we noticed we can clearly see from here that the upper branch corresponds to a compression wave that actually decelerates the flow and therefore we call it a detonation wave the lower branch is a expansion wave which accelerates the flow and so we call it a deflagration wave okay these are things that we noticed the next thing that we wanted to point out was we wanted to actually find out what is the speed at which the detonation waves travel and what is the speed at which the deflagration waves travel so the way we wanted to actually look at this what is the speed at speed of the lowest or the slowest detonation wave and what is the speed of the fastest deflagration wave and obviously we can see that they are sort of poles apart okay so that is the slowest detonation wave is still going to be much faster than the fastest deflagration wave so let us see what they tell us okay and these are corresponding to the Chapman-Jugey detonation and deflagration waves so what we want to actually look for is what is the incoming Mach number incoming Mach number at the CJ points at the CJ points on both branches alright so this is what we should be looking at now so how do you how do you locate the two the two CJ points right obviously you look at any point any point that is like a solution of both intersection of the Rayleigh line and the Hugoniot is by solving them together right so the Rayleigh line has its P infinity and 1 over rho infinity is showing up and the Hugoniot curve has its 1 over P infinity and 1 over rho infinity is showing up so that is to say that if you now solve for P infinity and 1 over rho infinity together with these two equations you now should get a pair of P infinity and 1 over rho infinity that corresponds to coordinates that satisfy both the equations and that means that that is a point where both of them intersect right but in addition to that at the CJ points we also have to match the slopes because the Rayleigh line is tangential to the to the Hugoniot curve right so so let us first try to get the end states at the CJ points end states as in the infinity conditions right so at the CJ points the slopes of the Rayleigh line and the Hugoniot curve match so that means we had a first of all find out what is the slope at any point on the Hugoniot curve and then match it to the slope of the Rayleigh line so that the slope of the Hugoniot curve is DP infinity D over D 1 over rho infinity this is something that you can actually obtain by simply differentiating the Hugoniot curve with respect to 1 over rho infinity right so wherever you are getting a P infinity you try to now differentiate that with respect to 1 over rho infinity right so then you get a P infinity minus P not times sorry minus 2 gamma over gamma minus 1 times P infinity divided by 2 gamma divided by gamma minus 1 1 over rho infinity minus 1 over rho 0 plus 1 over rho infinity that is the slope expression that you get for any point on the Hugoniot curve this is actually the slope at any point okay we are still not saying that this is at the at the CJ points at the CJ points it turns out that the slope should now be equal to the Rayleigh slope right so slope of the Rayleigh line what is the slope of the Rayleigh line Rayleigh line is a straight line okay and so long as we do not want to use the m dot squared expression that is like a no no yeah because we want to deal with only the thermodynamic properties so for a straight line it is just P infinity minus P not divided by 1 over rho infinity minus 1 over rho not that is it right so is P infinity minus P not divided by 1 over rho infinity minus 1 over rho not so equating the two equating the two we can we can we can get so we can get like a for example P infinity P infinity equal to P not rho not divided by rho infinity times gamma plus 1 rho not divided by rho infinity minus gamma so here what we have done is we have eliminated or we have now written expression for P infinity in terms of the other three P not rho not and rho infinity okay in fact we always should be looking for rho infinity to show up as 1 over rho infinity so sure enough this is 1 over rho infinity here this is 1 over rho infinity here and we are also getting it as rho not over rho infinity everywhere right here as well as here okay so essentially that means we should now be in a position to eliminate P infinity in favor of rho infinity or rather 1 over rho infinity or if you want to do it the other way you can now try to get an expression for 1 over rho infinity in terms of P infinity P not and 1 over rho not okay so or 1 over rho infinity equal to 1 over rho not times gamma P infinity divided by P not times 1 plus gamma rather you used to writing gamma plus 1 P infinity divided by P not minus 1 okay so you can use either of these expressions so these are both at CJ points both is both these expressions are valid at CJ points okay doesn't really solve much we have not really got the coordinates yet because here P infinity depends on rho infinity so what is it meant by saying getting the coordinates we should now be able to write P infinity only as a function of P not rho not and Q okay and 1 over rho infinity we should be able to write in terms of P not 1 over rho not and Q but this is the mixed thing we just can eliminate because we give you or we can write explicit expressions for P not at the seed P infinity at the CJ point and 1 over rho infinity at the CJ point in terms of the others which will still contain the other infinity term P infinity will contain 1 over rho infinity term and P 1 over rho infinity will contain P infinity okay so there are these other things so we still haven't solve the solve for the coordinates which is what we are now going to do next so substitute either of these right in the Hugoniot or strictly speaking say Rankine Hugoniot to give Rankine his new relation so that what happens is if you now write P infinity in terms of 1 over rho infinity in the Rankine Hugoniot you don't have P infinity at all in that expression you will now have an expression that is only on 1 over rho infinity which means you can now write what is 1 over rho infinity in terms of everything else right so to so but unfortunately you are now going to get a quadratic okay in either of these but it is actually fortunate if you physically fortunate mathematically a bit unfortunate you are dealing with quadratic equation but it is physically fortunate because this says only CJ matching the slope simply means that we have we are just working at any CJ point it could be the upper CJ point or the lower CG point either of these CJ points the really line is tangential to the Hugoniot it is not distinguishing between those those two right and we are therefore looking for two solutions to 1 over rho infinity and P infinity at the CJ points one of which will correspond to the upper CJ the other one corresponding to the lower CG point so here so substitute either of these expressions in the in the in the Rankine Hugoniot relation to get get a quadratic quadratic in either P infinity or 1 over rho infinity and solve solve the quadratic so if you now solve the quadratic you get P infinity plus or minus equal to P not plus gamma minus 1 Q rho not times 1 plus or minus 1 plus 2 gamma P not divided by Q rho not gamma squared minus 1 the whole to the half okay now let us call this small a the expression for P infinity plus or minus 1 and 1 over rho infinity plus or minus equal to 1 over rho not plus gamma minus 1 divided by gamma Q divided by P not times 1 minus or plus 1 plus 2 gamma P not divided by Q rho not gamma squared minus 1 so that is kind of like the same as what we had before to the half right okay so here what happens is when you now say plus or minus this plus goes with the plus here this minus goes with the minus here right but here this plus or minus is such that this plus goes with the minus there and this minus goes with the plus here right so when you say basically say plus or minus you simply mean upper CJ or lower CJ that means we are expecting that for the upper CJ your P infinity should always be greater than P not therefore P infinity plus will correspond to P not plus this okay lower CJ is going to be having a P infinity less than P not therefore P infinity minus should be equal to P not plus this minus with the negative sign that means you are going to have a less than and similarly here 1 over rho infinity you are not going to have 1 over rho infinity that is for the for the upper CJ you need to have a 1 over rho infinity that is less right therefore you need to have a negative sign over there and and for the deflagration CJ point the low LCJ point 1 over rho infinity is greater therefore you need to have a plus so the lower sign will always correspond to a LCJ upper upper sign corresponds to a UCJ right so upper sign corresponds to UCJ lower sign corresponds to LCJ so we now got the coordinates great so of course we need to call this be good I mean the in fact getting this with this particular thing or substitute those two expressions in the you go in your curve expression the rank and you go in your relation and get the quadratic and solve the quadratic to get these this is actually done for each of those separately right you will sweat a little bit it is going to take like some amount of time doing all this stuff okay well it could be a bit boring but you wait through the mathematics to see how the terms basically get grouped the way they are okay and then it is going to be pretty instructive for us because of what we are going to do next now what we want to do is what if what do we want to do what we want to do we want to now look at what is incoming Mach number why do you want to look at the incoming Mach number because we want to know how fast the CJ detonation wave and the CJ deflagration wave are going to travel right now keep in mind how fast as the wave going to travel is an information that is contained in U0 okay because in a wave fixed coordinate system you are going to have the reactance travel to the wave at that speed and that information is now in our scheme of things embedded in m dot because m dot is the one that is containing rho 0 U0 as well as rho infinity U infinity so it serves purposes of take carrying the flow information on either side of the wave right and since we are actually looking at the incoming Mach number we should be focusing on U0 that means we are looking at m dot through which we will try to look for rho 0 U0 and m dot does not show up in the Hugonio curve it is showing up only in the Rayleigh line right so we should now go back to the Rayleigh line and say it is sort of like saying look at whatever we have done we have substituted the slope matched information into the Hugonio curve to get this but can I now look at how the Rayleigh line is going to be like if I plug these coordinate points in the Rayleigh line and then get an m dot information through that is you what I am saying okay so in the we have really not used the Rayleigh line information except to note that that is the slope but that is just a thermodynamic that is just a slope written in terms of thermodynamic variables we have not brought in the fact that this is equal to minus m dot square right so that is what we want to do now so we want to now notice that the slope that we had that we had used for the Rayleigh line is actually equal to minus m dot square and then get to the flow information so using A and B in the in okay so simply just go back and write what it is P infinity minus P not divided by 1 over rho infinity minus 1 over rho dot equals minus m dot square right we can now get our m dot square divided by P not rho not plus or minus equal to gamma plus Q rho not divided by P not times gamma square minus 1 times 1 plus or minus 2 gamma P not divided by Q rho not gamma square minus 1 the whole to the half okay note that note that m dot equals rho not u not and the Mach number m not is going to be written as u not divided by a not which is nothing but u not divided by square root of gamma P not divided by rho not if you now notice that m dot is nothing but rho not u not so now now you write your u not is m dot divided by rho not okay so you now plug that over here you will now get your this is nothing but square root of m dot square divided by gamma P not rho not so we had m dot square by P not rho not all right okay and then we now are looking for m dot square by gamma P not rho not under square root is your Mach number or m not squared is now going to be m dot square divided by gamma P not rho that is what I mean this is something that is basic it is nothing particular about whatever we are doing this is like just putting these things together right so from here we should now be able to write m not plus or minus as 1 plus Q rho not divided by P not gamma squared minus 1 divided by 2 gamma the whole to the half plus or minus Q rho not divided by P not gamma squared minus 1 by 2 gamma the whole to the half so it is sort of like falling into some sort of a pattern there and this is what we were looking for so because it is going to say something to us so at the Cj points okay so what we can see from here is when Q goes to 0 right so when Q goes to 0 this goes to 0 this goes to 0 right so you just get m not plus or minus 1 is equal to 1 all right so when Q goes to 0 we get m not plus or minus 1 equal to 1 I can say goes to 1 and we will also see that m infinity plus or minus 1 at Cj points equal to 1 that is something that we will do next okay so what is about that simply means is nothing is happening when you do not have any heat release it is as if like you had a wave that is going at the sonic speed okay and not really changing anything about your gases the gases are basically non-reactive gases that means you do not you are not having any heat release and that is as if like you had gases go at sonic speed and nothing happened to it okay that is not a very interesting situation for us but let us now look at the other possibility what we are really interested in is when you have non-zero Q now how would you actually look for a non-zero Q in the Rayleigh line as I said when you now have a Q greater than 0 as Q increases you now have this Rayleigh line push up like that away and away from the origin of the Egonium right and as you now go up to Q turning to infinity let us say you now had Q going to infinity right this curve is going to actually go and hit the Rayleigh line that the Cj point is go get pushed to infinity and this Cj point is going to get pushed to infinity here alright and what you are going to now see is either your 1 over rho your P infinity is going to go to infinity or your 1 over rho infinity is going to go to infinity the P0 is going to go to 0 over here your 1 over rho your P infinity is going to go to 0 here and your 1 over rho infinity is going to go to the asymptote this is this is how it is going to push right so if you now look at the limit then so as strictly speaking do not have to look at Q going to infinity itself what really matters for us is in this expression Q ?0 divided by P0 goes to infinity then if you now use the positive sign for the UCJ that is a detonation wave then both these terms add up together towards each other and then the M0 plus goes to infinity right. So M0 plus goes to infinity but M0- goes to a 0 these two terms essentially subtract from each other of course one is like a small number when compared to these infinities that we are talking about so M0- goes to 0 right. So what this means is what you are then saying is then the for the Chapman-Jugey detonation wave detonation wave keep in mind when Q is equal to a 0 M0 plus or minus both of them are going to be equal to 1 that is a lower limit as far as the heat is concerned right. So for the Chapman-Jugey detonation wave we have M0 plus go from 1 to infinity right and for the Chapman-Jugey deflagration wave we have 0 less than M0- less than 1 you see so these are the limits that we are talking about therefore this is how it is going to pan and what that means is the M0 is not really going to overlap between these two okay. So this is going to go only up to 1 that is going to go only above 1 okay so that means a detonation wave travels at propagates at supersonic speeds and a deflagration wave propagates at subsonic speeds well let us not just then jump to that conclusion yet there is just one more step that we have already talked about the reason why and then I want to bring that in to generalize this quite well the reason why we were actually looking at M0 plus or minus at CJ points is keep in mind the CJ detonation is the slowest of all the detonation waves and the CJ deflagration is the slowest of all deflagration waves right so if you now have a CJ wave that is supersonic right that is a CJ detonation wave that is supersonic all other detonations are going to be supersonic because this is the slowest and if a CJ deflagration wave is going to be subsonic then all deflagrations are going to be subsonic right so the this implies that right all detonation waves propagate at supersonic speeds and all deflagration waves propagate at subsonic speeds so that is exactly what we were expecting or thinking will happen we also thought about a few things which is what happens downstream over here so if this wave is going to travel at supersonic speeds for detonation waves and compresses the gas the reactants as they now become products they are compressed they also decelerate so the question is or do they decelerate down to what okay so the answer there is they could decelerate down all the way down to subsonic conditions or they could get decelerated to supersonic conditions that are still slower than the incoming supersonic speed this is typically what you are expecting when you are now looking for a detonation wave that is not a CJ detonation so if you now have a any detonation right you can now have solution here and here and this is something that is going to correspond to a very high pressure and very low density sorry very high density as well very low one over density therefore we are expecting it to get a lot compressed and therefore lot decelerated so it can get down to subsonic speeds over here and on this side it is not going to be that much compressed therefore it is not that much decelerated so you could expect that this is not decelerated down to subsonic speeds but in supersonic yet less than slower than this the incoming supersonic speed and therefore we need to anticipate that at the CJ point the outgoing wave is actually going at sonic conditions right so this is what we need to anticipate and let us see if we can if that is going to work out so downstream Mach numbers at the CJ points right so what we then get is we had this expression that we we had this expression by matching the slopes of the Rayleigh and the Hugonio curves right for either the P infinity or the 1 over rho infinity which we substituted earlier in the Hugonio curve to get the coordinates of the CJ points all right and from there we now equated plug that value in the Rayleigh to get the m dot and from there we now went to the upstream Mach number but we can do something different here we have at the CJ points we have at the CJ points P infinity equal to P not divided by gamma plus 1 minus gamma rho infinity divided by rho not or 1 over rho infinity equal to 1 over rho not times gamma divided by gamma plus 1 minus P not divided by P infinity I think this is slightly different from what I just said a minute ago but it is possible for you to derive this by by dividing the numerator and the denominator appropriately by by by let us say P infinity and 1 over rho infinity and so on so it is supposed to have these what you did was you actually plug this into the Hugonio curve expression and got the quadratics and solve them to get the coordinates for the LCJ and the UCJ but if you can now go back and actually plug these in the Rayleigh line itself right so substitute either of these in the Rayleigh line equation and and note that this time we are interested in noting that m dot is not rho not u not because we are interested in the downstream conditions so m dot is actually rho infinity u infinity so note that m dot equals rho infinity u infinity right you should get right so to get simply get m dot squared equals gamma P infinity rho infinity now this is not very different from what we had over here you see you got as I told you we could have written this as m not m infinity is equal to u infinity divided by a infinity equals u infinity divided by square root of gamma P infinity rho rho infinity and then notice that plug this back in this here and then you can get m square m dot m dot square divided by gamma P infinity rho infinity if you got that and then by substituting this expression you also got this that simply means that m infinity is equal to 1 right so this is simply going to mean that m infinity plus or minus equal to 1 now in a mathematical sense this is not surprising because we plugged it we plug this expression in a Rayleigh line which is essentially linear right that is just a straight line therefore we are not expecting any quadratics right so if you do not have a quadratic then we cannot get two solutions we should get only one solution and that is only one solution okay we strictly speaking should not even write a plus or minus we are not even at this stage of distinguishing between plus and minus both of them are the same so that means we are basically looking for the same answer for the downstream Mach number in either of these points right there is to say the downstream Mach number at both CJ points right at both CJ points is unity this implies the CJ detonation decelerates supersonic reactant flow to sonic product flow and CJ deflagration accelerates subsonic reactant flow to supersonic product flow I am just going to abbreviate there because it is pretty obvious now if that is going to be the case so the next step that we do is to then say that if you got a strong detonation then strong detonation means supersonic reactant flow becomes subsonic product flow right CJ detonation is what we just saw supersonic reactant flow becomes sonic product flow and weak detonation becomes supersonic reactant flow all right but still supersonic product flow with M infinity less than M not okay you still have a deceleration weak deflagration means subsonic reactant flow becomes subsonic reactant flow still becomes subsonic product flow with M infinity greater than M not still less than 1 right so we should strictly speaking say with 1 less than M infinity less than M not the previous case here we should say with M not less than M infinity less than 1 right what we should say CJ detonation deflagration we saw subsonic reactant flow become sonic reactant flow sorry product flow and strong deflagration subsonic product reaction flow becomes supersonic product flow which is impossible because it violates second law which we have not explicitly considered mathematically and we will not do that just to accept to state that this is not going to be possible physically we will stop here for the day and we will try to wrap up this one on Monday.


All praise is due to Allah, the Most Gracious, the Most Merciful, who guided us to the straight path. The path of those who have the Book of Truth to judge among the people with what is special. The path of those who have the Book of Truth to judge among the people with what is special. The path of those who have the Book of Truth to judge among the people with what is special. All praise is due to Allah, the Most Gracious, the Most Merciful, who guided us to the straight path. All praise is due to Allah, the Most Gracious, the Most Merciful, who guided us to the straight path. All praise is due to Allah, the Most Gracious, the Most Merciful, who guided us to the straight path. All praise is due to Allah, the Most Gracious, the Most Merciful, who guided us to the straight path. All praise is due to Allah, the Most Gracious, the Most Merciful, who guided us to the straight path. All praise is due to Allah, the Most Gracious, the Most Merciful, who guided us to the straight path. All praise is due to Allah, the Most Gracious, the Most Merciful, who guided us to the straight path. All praise is due to Allah, the Most Gracious, the Most Merciful, who guided us to the straight path. All praise is due to Allah, the Most Gracious, the Most Merciful, who guided us to the straight path. All praise is due to Allah, the Most Gracious, the Most Merciful, who guided us to the straight path. He said to Abraham, my Lord, show me how to survive death. He said, I do not believe. He said, no, but I hope that my heart will be full. He said, every four of the birds, they will fly to you. Then He made every mountain a part of them. Then He called them, they will come to you as a shadow. And He knows that Allah is Mighty, Wise. The example of those who spend their money in the way of Allah, as an example of a seven-year-old girl in every village. And Allah is the One who wills. 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The path of those whom you worship, other than the subject, and to those who follow the truth. And Allah is the One who wills. And Allah is the One who wills. The devil wills. Allah is the One who wills. Allah is the One who wills. He wills. Allah is the One who wills. And Allah is the One who wills. All praise is due to Allah, the Most Gracious, the Most Merciful, who guided us to the straight path. The path of those whom you worship, other than the subject, and to those who follow the truth. And Allah is the One who wills. Allah is the One who wills. Allah is the One who wills. All praise is due to Allah, the Most Gracious, the Most Merciful, who guided us to the straight path. And Allah is the One who wills. Allah is the One who wills. Allah is the One who wills. Allah is the One who wills. Allah is the One who wills. Allah is the One who wills. Allah is the One who wills. Allah is the One who wills. Allah is the One who wills. Allah is the One who wills. Allah is the One who wills. Allah is the One who wills. The path of the straight path is guided. The path of those whom you have supported. Not the one who is blinded by them, nor the one who is blinded. They cannot see the darkness on earth. They think of it as a light. They ask no harm. They ask no harm.   Those who spend their wealth, hide behind them, nor grieve for them. Allah, hear Allah forever. Allah, Allah, Allah. As-salamu alaikum wa rahmatullahi wa salamu alaikum wa rahmatullahi. Allah is the greatest. Alhamdulillahi rabbil alamin. Ar-Rahman ar-Rahim. Maliki yawmin din. Iyaka na'budu wa iyaka nasta'een. Lihdina al-sirata al-mustakeem. Siraata al-ladyena an'abta aleyhim. Wa-yiril ma'rubi aleyhim wa l-abqaa. Al-ladyena y'aqtadiyat akhattatuhu shaytanu bin al-mas. Dahlika bil-annam qalbuhu. Innama al-bay'u mithlurriba. Wa-ahallahu al-bay'u wa harwama al-riba. Bi-ifan ma'salaf. Fala'u ma'salaf wa ammuhu ila Allah. Wa-man'aat. Innama al-ladyena aamanu wa amiru s-salifat. Wa-aqtadu s-salata wa atawzaka. Yemhaq Allahu al-riba wa yubi sadaqat. Yemhaq Allahu al-riba wa yubi sadaqat. Wa-Allahu la yuhibhu kulla kaf'anin. Al-ladyena aamanu wa amiru s-salifat. Wa-aqtadu s-salata wa atawzaka. Wa-aatawzaka ta-lahum. Ajaruhu binda rabbihim. Wa-la khawfun aleyhim. Wa-la hulya'zakuhu. Allahumma. Sama'Allahu niman hamidah. Allahumma. Yawm bideen. A'budu wa iyaka nasta'een. Ehdina s-sirata al-ustaqeem. Sirata al-ladyena an'amda aleyhim. Wa-iril ma'ubi aleyhim wa laqqat wa rasulih. Wa-intubtum falakum rusu. Amwanikum la tawlimu laqqat. Wa-inkana du'usratin. Fa-nadiratun ila meisarah. Wa-antasattaku khayru lakum. Inkuntum ta'lum. Wa-attaku yawna fiil Allah. Cummat wa dhaqul nafs. Cummat wa fhaqul nafs. Ma ke sabat wa mula yawm. Allahumma. Sama'Allahu niman hamidah. Allahumma. As-salamu aleykum wa rahmatullah. As-salamu aleykum wa rahmatullah. Allahumma. Alhamdulillah. Rahman ir-Rahim. Al-Maliki yawm. Al-Dili iyaka na'bud wa iyaka na'staqin. Ihdil us surat al-mustakir. Surat al-Ladina an'amta aleyhim. Wa-iril ma'ubi aleyhim wa laqqatun. A'iyaktuba ka ma'a'in. Haqq wa li-attakil laqqas. Minhu shay'a. Faa'in naqqusafiyan A'u da'ifan A'u la yasqatiha Faa'il yumlil Faa'il yumlil wari. Wa-stashidu shahidein Mir-rijalikum. Faa'il lamim aqasat Wa-ind Allah Wa-akwamu l-shahadat Wa-adha. Faa'iisa aleykum. Faa'iisa aleykum juna. Wa-ashidu Iza tabayatum. Wa-fusuqum bikum. Wa-attakil Sirat al-mustaqim Sirat al-shahadah Wa-mai'i Lillahi ma fis-sama'a. Wa-ind al-fusuqum. Wa-hasibkum bihi laa. Wa-hasibum bihi yashaa. Wa-allahu ala kulli shay'a. Sami'a Allah liman hamidah. Sami'a Allah liman hamidah. Sirat al-mustaqim Sirat al-mustaqim Sirat al-mustaqim Sirat al-mustaqim Sirat al-mustaqim Sirat al-mustaqim Sirat al-mustaqim Allah does not deny the soul except its ease It is not what it has earned and it is not what it has earned Our Lord, do not take us Guide us to the straight path The path of those who are on it Send down to me a true guide For what is between the most merciful How do you see the Wise? Hear Allah The straight path The path of those whom you have bestowed upon them It is not what it has earned It is what it has earned from it The straight path The path of those who are on it Send down to me a true guide For what is between the most merciful How do you see the Wise? The path of those who are on it Fight in the path of Allah And others who deny the soul For what is between the most merciful And Allah will guide with His help Who will grant the people the love of desires The pleasure, the pleasure, the pleasure The pleasure, the pleasure, the pleasure The pleasure, the pleasure, the pleasure That is what is best Hear Allah The straight path The path of those who are on it Send down to me a true guide For what is between the most merciful And others who are on it The straight path The path of those who are on it Send down to me a true guide For what is between the most merciful And Allah will guide with His help Who will grant the people the love of desires The pleasure, the pleasure, the pleasure The pleasure, the pleasure, the pleasure That is what is best Hear Allah The straight path The path of those who are on it و بكرمك الحقنا بالصالحين و لا تخيب رجاءنا فيك رحمتك من القوم و يسر الله و يتعسر بفضل وجود لا شفيته ولا ميتم إلا رضا و لنا فيها صلاحة إلا و في نسائنا و في رجال مجتمعنا دك الصالحين وتقب لله وما بفضلك صيامنا و صلاة انسختك والنار نسألك الجنة وفقنا لطاعتك و نحبتك و ما تحبه وترضاه اللهم انصر الإسلام والمسلمين و أدل الشرك والمشركين اللهم انصر من نصر الدين و أخذوا المنخذة للمسلمين و اجمع شملنا و واحد كلمتنا و زبنا ولا تنقصنا اللهم اعطنا من خزائن كلم الأب الخيرات اللهم ازدنا من خيراتك و بركاتك و انعم علينا كما انعمت على عبادك الصال كل شيء قدير و صل اللهم وسلم و بارك على سيد و الحمد لله


Thank you very much for having the perseverance and the gonadinal fortitude to stick around. At the end of the week you've had lunch and this is the talk that's going to put you to sleep or not. I will ask some questions and I am going to encourage audience participation. I was left ammunition up here so I may have to throw things. I had to give this a title and I put parenthesis around pervasive and the idea of cloaking. How many people in the room have a nick or some sort of handle that they use because they don't want to use their real name? We're going to talk a little bit about why you do that. Actually why do you do that? You don't get caught. Okay so we want to be protected against physical harm, plausible deniability, lawsuits, shorter than typing your own name, man after my own heart. The only problem is that when you create these digital identities you create a chain, a chain of custody. We're going to talk a little bit about that and what that means. First of all the disclaimer. My name is Bill Manning, it is not my nick, that's my real name. If you want to find me you can google me and you'll find five or six other guys named Bill Manning. Make sure you pick the right one. I'm currently employed by Booz Allen Hamilton in their analytics group and these are my opinions. I have not actually had these vetted by the company so hopefully they won't fire me when I go to work Monday. So I look at this as people have digital identities because they want to be in control. You want to control your own identity, your own destiny, I, me, I'm in control. My identity, I'm entitled to privacy and anonymity. I want to be able to be safe from physical harm when I say things that people don't like. I want to do things where I have plausible deniability. I want to be called anonymous. How many of you in here are called anonymous? Everybody raise your hand. You're all anonymous to some degree. So what you have is you have this sort of cloak that you wrap around yourself to hide. And that's what I mean by cloaking is that you hide your true persona and you project another persona out there. Unfortunately in these, in this digital or in this cyber domain it's a chain of trust. You can't unilaterally and independently create an identity and have it meaningful unless you share it with somebody. So the question is how long is your chain? You're going to be tethered to somewhere. So we're going to look a little bit in the back about how these chains were formed with crypto identity. Does anybody remember the crypto wars of last century? What was the result of the crypto wars? Phil Zimmerman. What was the result? The result turns out to be that there were some regulations that says you cannot export cryptography source code outside your country. This was actually pretty much applicable across all countries. Import and export of cryptography was considered bad. It was an artifact of war. It was ammunition and therefore was controlled that way. So there's sort of this blanket you can't do it. After the crypto wars, partly because of Phil Zimmerman and PGP and partly because of the DNSSEC work, those regulations changed. And now it's possible to actually move crypto software around. The problem here is what is this threat to anonymity if you have pervasive cryptography? I mean how many people need to know if you actually encrypt something in the previous talk? I encrypt something with a password and then I want to share that encrypted data. Somebody else needs the password. And then public key, private key kind of get around that, but you have to share. And as soon as you share, what happens to privacy? Anybody build tools to do eavesdropping so nobody knows what's going on? Liars. Or maybe they've already left town, maybe they're the smart people. So the responses are, very briefly, all of the cryptography, all of the crypto was considered prior to about 1998, was considered an artifact of war. And they had the laws. I covered most of this. From the internet perspective, the internet engineering task force, the ITF, has regular meetings. And they had a meeting in Danvers, Massachusetts in the mid-90s.  Great guy. He's dead now. They didn't pry it out of his fingers. What we have is we have strong crypto for authentication and identification was allowed and encouraged. That's why things like DNSSEC made it out into the world. And even the source for encryption. This little quote here is from the Department of Commerce from February 18, 2000, and it basically says, we throw in the towel. If it's open source crypto, even for encryption, you can send it. You can export it. We can't touch you. This is the general rule, except for some people. And this is where it gets dicey. These are the current regs. If you fall into one of those five categories, right, they can detain you. They can harass you. They can arrest you. Right? And it basically says, if you're somebody we don't like or we're suspicious of, we can hold you. We can make your life miserable. So previously it was nobody can do it. Now it's, if we think you're suspicious, you can do it. What's going to trigger the U.S. government's suspicion? Right? Well, that's one side. Let's move on to this next thing. There is a thing called NISTIC, and it has to do with trusted identities in cyberspace. This is a aspirational document from the White House that says, privacy and anonymity are important. They are core principles of this document. We think everybody in the United States is entitled to anonymity and privacy, except there has to be a trusted third party. Right? Previously the United States did this, and they did this with a project called Clipper, which was you have to give your keys to the U.S. government and trust them there, take care of you. Right? If I'm doing this wrong, throw something at me. Yes, you. You know this. No, no, no. Someone further back. So that was called Clipper, and basically people kicked at this, and they said, your ESCO policies are not sufficient, not good. We don't really want this. And so the government backed off, and now they're coming back, and they're saying, let's try this again. And this time you don't have to use the government, you just have to use somebody that we trust, right? And a few people looked at this, and they said, wait a minute, this is a national ID. And they came back and said, no, it isn't. Not really.   Right? And then everything will be hunky dory because we have these organizations, services, devices, individuals that can trust each other because we have these third-party authoritative sources. This morning's talk with Whitfield Diffie and Moxie, Moxie is really hot on this idea about these trusted authoritative sources. It's a little fuzzy on how that works, and we'll see that there's some problems there. The end result is if we've got this ecosystem defined by the U.S. It's kind of barren because there's only a few players that are actually going to meet potentially what the regulations require for a trusted third-party. It really boils down to who vouches for you. In real-world space, the people that vouch for you, how many people have got a passport? People have a driver's license, work ID, work badge, school ID, right? All of those institutions vouch for you, right? That's your nation state, the nation you're in, the state you're in, the organization you work for, the school that you attend. All of those things vouch for you, and they assemble this little chain that says that's really who you are, right? It's a pile of this together. Phil Zimmerman took a slightly different approach, and I think we see some of that in this community, which is that circle of friends. Who do you hang out with? Who do you share things with? Who do you swap keys with? And then there are a few people who do self-assertion. I don't really need anybody else. I don't need to have anybody tell me who it is. I am Prince. I am Madonna, right? Self-assertion, important people really want to do that by themselves, and the sociograph really says, you can do this. From a NISTIC expectation, whatever they pick as trusted third parties have to meet their guidelines, which are not defined. The question becomes one of, can bottom-up groups become approved NISTIC-branded, if you will, parties? I don't know. And so the idea here is that self-assertion is right out unless you are actually really famous anyway. The problem here is that aspirational document for NISTIC doesn't actually have the backing of any regulation, and this is where the trusted third parties break down. Does everybody use the same rules for keeping your private data? Do you have any rights to manage the data that you've been given, or that you're giving to somebody else? Can you control the distribution of that data? Do you have any feedback? Is there any sort of watchdog agency over the folks that manage your identity? How do you do this transient trust problem? And how do we have this idea about having meaningful voice in the development of policy for this stuff? None of that's really there yet. Those are open questions. So I look at this and I say, well, wait a minute, there's already an ecosystem out there that manages identity, and it's pretty robust, and it's got all this good stuff. So what the US government's really talking about is that we're going to approve this little corner in the lower right-hand side. That's going to be our little domain of trust. What happens if you're outside of the US? You've got a whole other part of that ecosystem that you can wander in and still not have a problem. So if I'm a multinational corporation, if I'm based in Bangalore, India, do I care about mystic and I don't do business in the US? Probably not, but I do care about tracking my employees, and it's probably associated with whatever regulations are inside India about managing digital identities. Similarly, if I'm in South Africa or if I'm in Taiwan or Japan, so if I'm outside, am I either a nation state or I'm a multinational corporation, the US rules are only a part of the landscape that I have to work in. And then there are these people that I call hobos. I hang out or used to hang out with a lot of people who spent more time on airplanes in more different places and had multiple passports from many different jurisdictions. Who do they report to? I don't know, right? Which rules do they follow? And it really boils down to who are the trusted third parties, trusted by whom? Do you trust your government? Where's your hand? Do you trust your government? All in favor? Say I. All against? Say I. I trust my government to not have my best interests at heart most of the time. You can put it on a T-shirt, I'll take 10% off the top. And then there's this idea of self-identification.  Am I really? How do you know? Right? So there's this idea about trusted by whom. There are, if there was a trusted third party and this woman had given her digital identity, her credentials, her secret keys to this trusted third party, would the U.S. Department of Justice be asking these questions? Does anybody know what this is going on here? Right? Would they, I mean, basically what they're doing is they're saying, we want a trusted third party and we think that probably one of the rules of being a trusted third party under our program is if there's a warrant, you have to give us somebody else's data that they've escrowed with you. Do I want that? I don't know. Maybe. Maybe not. You don't want that. You really don't. You don't want me to hand over to my fed buddy over here. Yeah. I mean, you don't want me to hand that data over to them, right? Just because you told me something? Don't give it to me. If I don't have it, I can't give it to somebody else, right? So from a law enforcement perspective though, they have some real legitimate reasons for tracking people and identities and stuff, right?  Because then they have to correlate and data mine many, many more sources of data to try and actually track the patterns that identify you, but they'll do it, right? And then there's this other part that we haven't really talked about much, which is market forces. If I'm going to become one of these trusted intermediaries, I'm going to become this notary unless there's some explicit provisions for me to not share your data. I'm going to collect this big database and the first thing I'm going to do is I'm going to go to my board of directors and say, see, we've got all of these clients. They're going to go, how do we monetize this data? They're going to want me to sell the data either individually or in aggregate to other people so we can make more money. And so what I'm doing now is I'm actually creating a two-faced thing. I talk to my people that say, register with me. You can trust us. And out the other side of my face I'm saying, look at all this nice, interesting, aggregated data that talks about people that use this service, right? That's a false sense of security on the part of users because I think I'm protected, but my intermediary, my trusted third party, isn't, right? So they're going to collect my data. They're not going to tell me about it. And they're going to commoditize that data with aggregates with everyone else. Just for grins, what if somebody collected all the data for all the attendees at DEF CON and sold that, right? Bad idea, right? And then there are always, and this came up this morning again, is the budget trusted identity or trusted identity ecosystem provider. We're going to hold your personal identity, your data, your shot, 10, 24-bit keys using high security. Actually, it's kind of like high security. We're over here. You're over there. We're going to put it in this nice little digital locker. We're going to protect it with really, really strong security. Wrote 13. My dog can decrypt, wrote 13, and my dog is dead, all right? We're going to put it in an Excel spreadsheet on this XP-connected cluster directly connected to the internet for $20 a month. What a deal, right? So the real problem is, is that when you actually see the emergence of multiple providers, people wanting to be your trusted third party, there's no regulation, no information about how these people should operate and protect your data, right? There's nothing. That still needs to occur, right? So I'm going to ask the question. Is anonymity analog or digital? Where digital, I mean, is it binary? Am I either anonymous or am I completely exposed? Or is it more of an analog thing? I can show you a little bit, but I'm going to show these guys more, right? Which is it? We have a vote for analog. All in favor of analog, say, I. Why are you raising your hands? Can't you follow instructions? Digital, binary, OK. Both. How is it both? Why not? OK, so what I'm telling you is that I have exposed to you a couple of bits of information about myself. My employer, my name, and the fact that I'm sitting here at DEF CON. I have given you nothing else, right? I haven't given you my date of birth. I haven't given you my mother's maiden name. I haven't given you my social security number. I haven't given you my private keys. I haven't given you my credit card information, my bank account number, any of that stuff, right? I've only given you two bits of information, exposed a little bit. Other people over here know more about me than that, all right? So I think it's kind of a continuum when you think about anonymity. You cannot be completely anonymous, I don't think. And the real kicker for me here is that we are known by the company we keep. I can try and be anonymous, but unless I'm actually using something like Route 13 where I have plausible deniability, all right? If I'm using strong crypto, I'm trackable. Or my strong crypto is trackable. And as soon as you can track me, all you have to do at one point in time is to correlate that digital identity with me, and then you've got my entire history of what happened. And I have no longer any sort of plausible deniability. This is a weakness with people using strong crypto. And then there's this question, what does it mean to be or to remain anonymous? In the 1930s, there was a cartoon called Betty Boop. Anybody remember Betty Boop? That would be the old school people. Remember Betty Boop, right? And Betty Boop had one of the things in 1930, actually, in 1929, there was a character that emerged called Mysterious Moes, which turned out to be an artifact that frightened the socks off of this poor lady and everybody else, including the guy who was running it. It turns out it was a fabricated identity that nobody really knew anything about. And so if we attempt to be anonymous or attempt to maintain our level of privacy, you need to be a little bit worried because sometimes those things can turn on us. And at the end of the day, the problem is how do you manage your digital identity and trust chains? Can you do it alone? How much information have you shared with others and can you be assured that they haven't shared it with other people? And how do you revoke information that's bad? Help me, give me an answer. I'm sorry? Whatever I put out there is out there and I can't recover it, right? You know what's scarier? Whatever you put out there about me is non-recoverable. And you may be lying through your teeth about me and I have no idea, right? So there's this whole idea about actually being able to manage the digital identities that you create. And I don't know that we should create too many. So I'm gonna start wrapping up here. The digital identity or identity ecosystem or online persona or however you wanna call it, all of those things map back to meet space identity where existing law and rule applies. I'm sorry, John Perry Barlow, there is no independence in cyberspace. It all maps back to meet space. Then that would be a admission that I attended the California State public schools when I was little and I didn't spell check. Please feel free to correct the spelling errors, all right? So nobody is really isolated after this stuff.  And everyone, to some degree or other, is partially cloaked. Nobody knows everything about you. Conversely, everybody is partially exposed. Somebody knows something about you. Maybe many people. I hope that no one goes and knocks on my parents' door and asks them about me because they're gonna get all kinds of stories about how I was as a little boy. I don't want those stories getting out. The point being is that there is a trail. Everybody leaves a trail. The more you work in the digital space, those trails are actually more persistent than the ones in real world. Because nothing is ever really erased or gotten rid of. There are always copies around some place. And people make money going and investigating those trails. Additionally, if you build tools to try and hide yourself, those tools will be distributed. If they ever show up on the internet, they will get copied. And they will be used contrary to your interests. This is a war of escalation. The more we try and hide, the more people try and uncover what we're doing. And they use the same tools against us that we use against them. So the advice here is to choose your traveling companions wisely. Be very comfortable in who you trust with your digital identities. Anchoring this back to NISTIC, it's still being formulated. There are some discussions going on. And it's not too late to influence the outcome, particularly when it comes to the sets of regulations that are going to describe and regulate these trusted third parties. So if people in this community want to influence what the US government is likely to do, it's an opportunity to do that. And it really boils down to, this is something I mentioned this morning, is the idea of influence ripples. As soon as you do anything, it affects somebody else. And that affects how they interact with other people. And so your influence, the things that you do online, ripple out and affect a larger and larger community. And you cannot recall that information. So it's important to be very careful in what you do. And that's my presentation.