WEBVTT 00:00.000 --> 00:01.640 I get to cheat. 00:11.310 --> 00:12.670 All right. 00:15.750 --> 00:17.630 And we're live. 00:18.030 --> 00:19.190 All right. 00:19.190 --> 00:26.090 So we're here with Mike Stay, another fantastic speaker for virtual DEF CON safe mode. 00:26.330 --> 00:34.250 He is covering how he recovered a six digit sum of worth of Bitcoin from an encrypted zip file. 00:35.130 --> 00:43.250 And I guess if you just want to like quickly go into your talk, spend just like a minute or two, and then we'll start asking you some questions. 00:43.470 --> 00:44.470 Yeah, sure. 00:44.470 --> 00:51.070 So short summary is I used to work as a reverse engineer back in the late 90s. 00:51.150 --> 00:58.690 I broke the zip encryption that was used by InfoZip, which was the open source version. 00:58.690 --> 01:07.990 And so everybody accepts PKZip based their encryption on that, particularly WinZip that had like 95% of market at the time. 01:08.470 --> 01:18.370 And yeah, so then 20 years later, somebody locked up their Bitcoin in a zip file that they made on their Linux box and forgot the password. 01:18.730 --> 01:22.790 So they came to me and said, hey, I found your paper. 01:22.990 --> 01:24.710 What's the current state of the art? 01:24.710 --> 01:25.930 Can you help me with this? 01:26.890 --> 01:29.670 And this is your first time talking at DEF CON, right? 01:29.670 --> 01:30.390 Yes. 01:30.450 --> 01:31.090 Yep. 01:31.210 --> 01:36.370 So we've given him fair warning, but there is a tradition for first time speakers of DEF CON. 01:36.670 --> 01:39.510 They get to take a shot with us on stage. 01:39.630 --> 01:41.850 QA session is the closest thing to a stage. 01:41.850 --> 01:45.910 So thank you, Mike, for providing DEF CON with some wonderful content. 01:46.050 --> 01:47.290 Cheers to you, man. 01:47.530 --> 01:49.350 Thank you for having me. 01:52.780 --> 01:54.220 All right. 01:58.040 --> 02:00.880 Okay, so I was actually kind of surprised. 02:00.880 --> 02:07.920 So I have never thought about zip encryption as being something that would be difficult to get around. 02:07.920 --> 02:10.420 You did go into a couple of different types of encryption. 02:10.420 --> 02:16.620 I was also surprised that like, well, I wasn't surprised that early word was as difficult as it was. 02:16.620 --> 02:22.500 But later on, the 40-bit encryption that was just really difficult to brute force, that one kind of surprised me. 02:22.500 --> 02:33.120 Do you have any other... have you worked with any other type of encryptions that have been surprisingly difficult to get into for being such a legacy, weird proprietary protocol? 02:34.860 --> 02:36.100 Let's see. 02:38.950 --> 02:50.510 There were a couple where they clearly knew enough to be dangerous, but then completely screwed it up. 02:50.510 --> 02:52.750 Like early word perfect. 02:54.390 --> 02:59.390 You know, the founder of the company had broken that one himself. 02:59.570 --> 03:05.870 And then when they released their new version saying, oh, now we're using strong crypto, nobody will be able to break this. 03:05.870 --> 03:18.250 Went in and found that they took the password and then ran it through DES in the wrong way and got out some vector and then just XORed their file with it or something ridiculous like that. 03:18.250 --> 03:21.410 So they had DES, but they didn't use it right. 03:21.410 --> 03:22.710 It was so close. 03:22.850 --> 03:23.170 Yeah. 03:23.950 --> 03:25.550 There were ones like 03:29.170 --> 03:36.990 Microsoft Access 97, I think was one where they had RC4 encryption, but it was a fixed key. 03:36.990 --> 03:46.170 And so they would RC4 encrypt the file with this fixed key and then you'd go to this offset in the file and look up the password and it was just sitting there in plain text. 03:48.230 --> 03:50.510 Some of the details might be off. 03:50.510 --> 03:51.610 It's been 20 years. 03:51.610 --> 03:52.330 Fair. 03:54.110 --> 03:56.270 Go ahead. 03:56.570 --> 04:05.850 I want to ask a really, while we wait for people to come up with some really good technical questions to throw at you, I'm going to do one that... all right. 04:05.850 --> 04:09.970 So let's say that I don't know everything there is to know about encryption out there. 04:10.230 --> 04:16.050 Let's say I want you to do... I'm going to ask you to do a similar thing that you did in your talk. 04:16.050 --> 04:22.350 And I know that my password starts with a word and has some unknown thing after that. 04:22.350 --> 04:29.350 Are there things that I can provide you that I might know about the password that will help you get through this? 04:29.350 --> 04:33.230 Or does the encryption work in such a way that that doesn't mean... 04:33.230 --> 04:34.630 Dictionary attack, right? 04:34.730 --> 04:38.010 The product you're using has strong crypto. 04:38.010 --> 04:41.250 The guys that built it knew what they were doing. 04:41.250 --> 04:44.850 Then pretty much a dictionary attack is the only option you've got left. 04:44.850 --> 04:52.490 And so there are specialized attack software that you can get. 04:52.490 --> 04:53.910 One of them is called Hashcat. 04:54.290 --> 04:58.190 It's built for running on GPU farms. 04:58.190 --> 05:03.070 That was what we were originally looking at is maybe writing a Hashcat module for this. 05:03.070 --> 05:06.470 But it's really designed for processing a key space. 05:07.490 --> 05:10.010 And so you can give it a dictionary. 05:10.010 --> 05:18.950 You can then say, take this and then do all alphanumeric strings up to length six after it. 05:18.950 --> 05:22.790 Or take this and try all different capitalizations. 05:22.830 --> 05:25.650 Replace vowels with numbers. 05:25.650 --> 05:29.970 Say, you know, an I goes to a one or an O to a zero and so on. 05:29.970 --> 05:31.030 E to a three. 05:31.030 --> 05:41.410 Whenever you do that sort of thing, you can... there are these rule sets that you can say, okay, Hashcat, this is what you're going to start with and these are the rule sets that I want you to use when processing it. 05:41.410 --> 05:45.830 Because this is best in my memory what the password looked like. 05:45.970 --> 05:52.450 On the other hand, if you're doing something like correct battery horse staple from XKCD, you've got too much entropy. 05:52.450 --> 05:57.590 And that's really the way to protect your files if you're doing something is just make it longer, right? 05:57.590 --> 06:09.650 Because if you go from 26 characters, which is, you know, lowercase letters, to 97, you've roughly tripled. 06:09.650 --> 06:17.190 That's adding two bits per character to the entropy, right? 06:17.190 --> 06:27.410 So if you've got a length eight password, 26 to the eighth has, you know, all possible lowercase letters there. 06:27.410 --> 06:32.410 But if you go up to 97, all printable characters, that's only adding two bits per password. 06:32.410 --> 06:34.430 I'm sorry, two bits per character. 06:34.610 --> 06:41.250 So on a length eight password, that's, let's see, 26 is about five bits. 06:41.250 --> 06:42.750 That's 32. 06:43.250 --> 06:45.530 And two times eight is 16. 06:45.530 --> 06:48.390 So it's adding three characters to the length of your password. 06:48.450 --> 06:55.770 Adding printable characters to a password of the same length, you know, it's just adding a few more. 06:55.770 --> 07:04.250 But if you go and add a whole bunch more characters to your password, make it a long one, that'll make it really secure. 07:04.750 --> 07:08.630 Use a passphrase instead of a short random string. 07:08.670 --> 07:20.990 Yeah, and so if you, even if you're using English words, right, if you make it a passphrase rather than password, that'll make it really so vulnerable to a dictionary attack. 07:20.990 --> 07:26.530 There may be other attacks if the crypto is bad, but if the it'll protect you. 07:26.790 --> 07:30.130 So just this is entirely for my own curiosity. 07:30.130 --> 07:36.570 So after you broke through this zip file, you got the password that you could use to decrypt the zip file? 07:36.570 --> 07:37.830 No, we didn't recover the password. 07:37.830 --> 07:39.050 Oh, you didn't recover the password. 07:39.050 --> 07:39.350 Okay. 07:39.350 --> 07:39.550 Yeah. 07:39.550 --> 07:44.950 So the way the way zip works is it derives a 96 bit key from the password. 07:44.950 --> 07:47.410 And it was 96 bit key that we recovered. 07:47.410 --> 08:00.010 Now, if we wanted the password, we could take those 96 bits and then go launch a hashcat attack using dictionary and and some other stuff that that others have have worked out to get a few of the initial characters. 08:00.290 --> 08:05.130 That's where it fits into the type of password cracking that many of us are familiar with. 08:05.130 --> 08:06.490 Hashcat or John the Ripper. 08:06.490 --> 08:07.150 Okay. 08:07.290 --> 08:15.830 So if you've got the 96 bits, then there's something you can do with the dictionary attack that'll see whether the initialization process gives you those bits or not. 08:15.830 --> 08:16.790 That's great. 08:16.790 --> 08:25.770 Yeah, what I was going to ask is if you got far enough to see if like a dictionary attack would actually work against the zip file in less time than you spending all this time to brute force it. 08:26.610 --> 08:39.570 But if you didn't... He suspected it was on the order of, you know, 20 something characters or more, so it took him quite a while to to brute force. 08:39.570 --> 08:43.570 Would this technique that you went through work for any encrypted zip file? 08:43.930 --> 08:45.030 Yeah, yeah. 08:45.030 --> 08:47.410 This will work on any zip file with... 08:47.970 --> 08:56.290 So my original attack back in the late 90s required five bytes, five files in the archive with the same password. 08:56.290 --> 09:04.130 This one we were able to get away with two because we also knew the the timestamp. 09:04.150 --> 09:10.530 So if you've got the timestamp and you've got two files, then this will work on any of them. 09:10.530 --> 09:15.030 So how does the number of files affect the craftability of the zip file? 09:18.770 --> 09:21.450 When... Suppose you don't have the timestamp. 09:21.450 --> 09:21.970 Okay. 09:22.190 --> 09:27.770 In InfoZip, it was meant to run on Unix machines as well as Windows machines. 09:27.770 --> 09:32.250 So on PKZip, they just allocated some memory and used whatever bytes were there. 09:32.250 --> 09:34.090 Those random bytes. 09:34.090 --> 09:39.270 In InfoZip on many Unix machines, it would initialize the bytes to zero. 09:39.270 --> 09:41.250 And so there would be no randomness there. 09:41.250 --> 09:52.630 So they used the process ID and the timestamp to get a little bit of entropy and then fed the XOR of those two into C's RAND function and generated a bunch of bytes. 09:52.630 --> 09:55.710 But they thought maybe that's too weak, right? 09:56.050 --> 09:59.170 There were some known plain text attacks. 09:59.170 --> 10:08.670 And they're like, well, if they brute force the timestamp and the process ID, then they can derive the rest of these bytes. 10:08.670 --> 10:12.690 And so they took the password and encrypted those bytes once. 10:12.810 --> 10:17.570 And that's what they used as the random bytes when they encrypted that and the rest of the file. 10:17.990 --> 10:26.070 But when they encrypted it twice, because of the way the ZipCypher works, it produced the same stream byte twice at the beginning. 10:26.070 --> 10:31.590 So it encrypted it once and then it decrypted it for the first byte of each file. 10:31.590 --> 10:34.470 So when you say that, is it files in the archive? 10:34.470 --> 10:47.270 I have every 10th output of that C's RAND function and 40 bits were enough to figure out the 31-bit internal state of C's RAND function. 10:47.270 --> 10:53.270 So once I knew the internal state of C's RAND function, I could generate those first 10 bytes of each file. 10:53.270 --> 10:56.590 And then I would do a bunch of bit guesses. 10:56.590 --> 11:04.810 And because of the way the Cypher was designed, not all 96 bits were used when producing each output byte of the stream. 11:05.130 --> 11:08.790 So I guess like 40-something bits up front. 11:09.070 --> 11:14.930 And then because I had five files there, and I knew what those bytes had to be, I could filter all of those bits. 11:14.930 --> 11:22.050 I could say, I've got to know which of these 40-bit guesses are correct before moving on to the next stage. 11:22.050 --> 11:22.250 Got it. 11:22.250 --> 11:33.370 And so by having five files, I could both derive the internal state of C's RAND function and filter my guesses and finish one stage before moving on to the next one. 11:33.370 --> 11:35.850 And so it was a parallel divide-and-conquer attack. 11:35.850 --> 11:38.830 In this case, I only had two files. 11:38.830 --> 11:44.070 So even though I was making a 40-something-bit guess, I only had two bytes to filter it with. 11:44.070 --> 11:51.630 So I, you know, that meant 2 to the 24th wrong key guesses went to the next stage, and I had to guess more. 11:51.630 --> 11:59.330 And so it just kept getting bigger and bigger and bigger up to 2 to the 60-something before I could start paring it down at the other end. 11:59.330 --> 12:05.550 So just for clarification, it's resetting the stream cipher every single time it encrypts a separate file, and that's why you're able to do this? 12:05.710 --> 12:06.690 Yes , yeah. 12:06.690 --> 12:11.630 So it starts over again with the same password, resets it to the original state, and starts from there. 12:11.630 --> 12:17.190 Because you want to be able to extract a single file from the zip file without having to extract all of them. 12:17.190 --> 12:17.650 That makes sense. 12:17.650 --> 12:23.590 I think you just answered one of the questions we got with the new attack, is there an acceleration in having more files in the archive? 12:23.590 --> 12:24.890 Absolutely. 12:24.890 --> 12:29.050 I mean, in the original attack, the more files you had, the faster it went. 12:29.990 --> 12:33.450 And so this is just a refinement of the original attack. 12:34.650 --> 12:40.670 But certainly having more files means more bits to filter with, and getting rid of false positives earlier. 12:40.910 --> 12:50.090 And sort of closely associated with that, do you know if this kind of attack works with the other encrypted archives like 7-zip and RAR? 12:50.090 --> 12:56.070 Most archival software now uses AES, like RAR5 switched to AES-256. 12:56.070 --> 12:59.450 So this isn't going to work against anything except zip files. 12:59.690 --> 13:02.330 Going for best standards, I like to see that. 13:02.490 --> 13:06.370 Even WinZip switched to AES a while ago. 13:06.370 --> 13:07.470 Fair enough. 13:08.330 --> 13:10.370 We had another question. 13:10.770 --> 13:15.090 Do you know if your client was the legit owner of the Bitcoin? 13:15.970 --> 13:23.690 I can't be certain, but we looked him up online. 13:23.710 --> 13:29.310 We knew his real name, and we looked him up online and found that he had reason to be owning Bitcoin. 13:29.870 --> 13:31.350 It didn't seem too shady. 13:31.350 --> 13:34.610 It wasn't someone reaching out across the dark web from... 13:35.470 --> 13:38.610 It was part of his employment that he would be dealing with Bitcoin. 13:38.610 --> 13:39.610 Fair enough. 13:43.250 --> 13:45.070 No, that makes sense. 13:45.070 --> 13:47.530 So this is really interesting. 13:48.510 --> 13:59.010 Do you expect with putting this out here and providing this talk, do you expect to get more of these requests to crack more things? 13:59.010 --> 14:06.190 If you do get more of these requests, do you have an answer pre-built of how you might respond? 14:06.190 --> 14:19.090 As far as breaking into Bitcoin wallets, yeah, when I first wrote this up on my blog, we got a whole bunch of requests. 14:19.470 --> 14:25.090 And for most of them, I had to say, nope, sorry, the best you can do is a dictionary attack. 14:25.090 --> 14:30.730 Many of them said, you know, I bought Bitcoin with a credit card ages ago, but now I can't find my wallet. 14:30.730 --> 14:31.450 Can you help me? 14:31.450 --> 14:33.470 I've got my credit card records. 14:33.830 --> 14:35.570 No, we need a little more than that. 14:36.250 --> 14:46.210 The one that was most interesting was a guy who claimed that his hard drive had crashed, that had Bitcoin on it. 14:46.210 --> 14:48.650 And so we were working with him to get some data recovery. 14:48.650 --> 15:00.090 But after a while, it became clear that he was perhaps schizophrenic or delusional, that he believed that someone was cheating him out of his Bitcoin and had stolen. 15:00.090 --> 15:03.190 Anyway, it was interesting. 15:03.190 --> 15:10.670 That said, there are about four situations where we could potentially recover software. 15:10.670 --> 15:20.710 One of them is if you printed out or wrote down the seed phrase for generating the 128-bit key, right? 15:20.710 --> 15:25.550 When you generate it, the wallet software always says, keep this in a secure place, right? 15:25.550 --> 15:32.150 And it's this 30-odd word phrase that'll generate the 128-bit key. 15:32.150 --> 15:35.570 If you've got that, you can recover the key, you can recover all your Bitcoin. 15:36.210 --> 15:44.050 The next case is if you have had damage to your hard drive, right? 15:44.050 --> 15:49.190 If the hard drive crashes, then the data in the sector is probably okay. 15:49.270 --> 15:57.090 And even if the data in the sector is bad, we only need eight bytes to be okay, that has the encrypted key in it, right? 15:57.090 --> 16:01.030 So if we can recover that data, then we can probably recover your wallet. 16:01.790 --> 16:12.290 If you have the wallet software, you don't have the original phrase, but you know you used a weak password, then we can try and do the dictionary attack approach. 16:12.930 --> 16:23.670 And then the least probable, there have been wallets with security flaws that make them susceptible to breaking more easily. 16:23.670 --> 16:32.530 And if you happened to use one of those back when they were being used, most of them have been fixed since then. 16:32.530 --> 16:36.830 But if you happen to use one that had a flaw, then we could try to exploit that flaw. 16:36.830 --> 16:44.750 Yeah, so this was an attack on a zip file, but you're talking directly about Bitcoin wallets. 16:44.750 --> 16:49.530 Do they also use some zip-like structure? 16:49.530 --> 16:52.230 Have you attacked the Bitcoin wallets themselves? 16:52.890 --> 17:08.650 The Bitcoin wallet takes the key, the private key information that you sign your transactions with, and a password, and generates a symmetric key from the password and some salt, and then encrypts the private key. 17:08.830 --> 17:12.050 So that private key is really what gets you access to the Bitcoin. 17:12.050 --> 17:20.270 What we can do is try to either recover the private key by means of that really long phrase, regenerate that same private key. 17:20.890 --> 17:27.090 Or we can attack the password, if you've got the wallet, so that we can decrypt the private key that you had stored. 17:27.090 --> 17:40.370 Or we can attack some flaw in the cipher where, for instance, when they were coming up with the symmetric key, they didn't use the entropy properly. 17:40.370 --> 17:43.590 And so there's a much smaller key space that we would have to brute force. 17:43.750 --> 17:47.970 There are very few of those that were out there, but there were some. 17:48.550 --> 17:50.930 There's a possibility we could do that. 17:52.450 --> 17:57.890 So I like asking this question to people who know this technology really well. 17:57.890 --> 18:06.410 Feel free to tell me, no, you're not going to answer this question, but do you yourself hold any value in any cryptocurrencies? 18:06.410 --> 18:08.790 Because you seem to understand how it works. 18:09.430 --> 18:17.750 Um, I don't, because I have... I mean, there's no inherent... 18:22.400 --> 18:28.260 When you pay taxes, you pay taxes in dollars, because the government says you have to pay taxes in dollars. 18:28.260 --> 18:33.520 So there is this built-in necessity to own dollars at some point. 18:33.520 --> 18:39.320 There is no built-in necessity to own Bitcoin or any other cryptocurrency, right? 18:39.320 --> 19:03.940 There's... and for Bitcoin and Ethereum, I think that proof of work has shown itself to be susceptible to attacks like Sybil attacks, 51% attacks, like Bitcoin Cash and Ethereum Classic have both suffered 51% attacks. 19:03.940 --> 19:12.720 They were, you know, rebuffed eventually, but, you know, if Google wanted to deploy their whole infrastructure, they could completely own Bitcoin. 19:12.760 --> 19:19.480 There are existing companies that could do that, not to mention nation states, right? 19:19.480 --> 19:29.080 If the US wanted to take it down, they've got this thing in Tooele here in Utah that they could deploy against taking down Bitcoin. 19:29.080 --> 19:43.280 So my personal take, and we designed a system to do this, is that you need to use a consensus algorithm with true finality, that proof of stake and bandwidth. 19:43.780 --> 19:49.740 And then after a certain point, when you have enough witnesses, you say, this block is finalized and it can't ever change. 19:50.280 --> 19:55.660 Ethereum is trying to move in that direction with their proof of stake algorithms, but... 19:56.680 --> 20:02.220 Yeah, I've heard of proof of stake, but the finality piece is new to me. 20:02.880 --> 20:06.860 You've definitely given me a few pieces already that I'm going to need to go Google. 20:07.320 --> 20:10.680 So we got another question. 20:10.720 --> 20:12.920 It's sort of a meta question. 20:14.960 --> 20:19.400 One of the people that watched your talk had a little bit of struggle following your math. 20:19.400 --> 20:27.800 They understood all the aspects individually that you talked about, but zooming back out, they seem to lose pieces in their head. 20:27.800 --> 20:32.000 And they want to know, how do you juggle this? 20:32.000 --> 20:38.880 Are you aware that some people that follow your talk might have difficulty zooming in and out like that? 20:39.080 --> 20:39.680 Yeah. 20:39.680 --> 20:46.380 So I had some options when doing this talk. 20:46.380 --> 20:50.780 One was to go really deep and really hard on the technical stuff. 20:50.780 --> 20:58.860 Another one was to give enough background and the basic idea of how this attack played off and the challenges we faced. 20:58.860 --> 21:07.320 So I chose to be less detailed for the sake of the story rather than go deep into it. 21:07.600 --> 21:11.400 If anyone has any technical questions, take them offline. 21:11.400 --> 21:15.720 I'll be happy to talk through them with you and point at lines of code and that sort of thing. 21:15.720 --> 21:16.540 That's great. 21:16.540 --> 21:17.140 That's awesome. 21:17.420 --> 21:25.240 As far as keeping it in my head, I would have to wake up and then come down and reload everything. 21:25.240 --> 21:28.540 I had stuff on whiteboards all over my office, pictures. 21:28.540 --> 21:29.900 It was a process. 21:29.900 --> 21:35.640 I would even have to remind myself about what was going on because I couldn't keep it all going at once. 21:35.640 --> 21:45.900 And it was a months-long process of trying to think through over and over again how things are going wrong and what I might be able to do to fix it. 21:45.900 --> 21:52.340 So if you don't get it from one short 45-minute talk, I certainly don't blame you. 21:52.640 --> 21:53.980 Makes sense. 21:56.620 --> 21:58.580 Did we discuss this at the end? 21:58.580 --> 22:00.520 I'm sorry, I missed this point. 22:00.540 --> 22:03.660 Did you actually get any compensation for this work? 22:03.960 --> 22:04.760 We did, yeah. 22:04.760 --> 22:08.880 So when he first talked to us, we said we'd like so much up front. 22:09.180 --> 22:12.120 We estimate that the total cost will be about this much. 22:12.680 --> 22:15.460 We took longer than we said we would. 22:15.600 --> 22:19.240 We expected it to be done in three months. 22:19.360 --> 22:22.340 That was October, so November, December, January. 22:22.340 --> 22:28.220 It was April before we actually, late March, before we actually got the key back. 22:28.240 --> 22:35.920 But because of all of the extra cryptanalytic work that I did, it took a tenth of the time on the hardware. 22:35.920 --> 22:45.060 So the hardware cost ended up being only roughly 10, 15 grand as opposed to the 100 grand that we thought it would take at the beginning. 22:45.060 --> 22:47.840 So we gave us a bonus afterwards, which was nice. 22:47.840 --> 22:50.400 I actually missed this. 22:51.180 --> 22:55.880 Another one of the speaker goons mentioned that it was on AWS. 22:57.220 --> 23:03.740 And they want to know if the 10 to 15 was about what you were expecting from compute cost. 23:04.240 --> 23:07.180 No, we were expecting it to take far more. 23:07.180 --> 23:18.460 The original estimate was around 2 to the 64th work, which is comparable to finding a collision in SHA-1, which is 100... 23:20.240 --> 23:22.260 Sorry, SHA-1 was 160. 23:22.260 --> 23:25.740 MD5 was a 64-bit thing. 23:26.140 --> 23:37.500 And there were some recent work where to find a collision, they had to deploy an enormous amount of work to do it. 23:37.500 --> 23:43.460 I guess MD5, they were able to do because of flaws in the hash function. 23:44.200 --> 23:51.280 SHA-1 took roughly 100k of GPU time to break. 23:51.280 --> 23:55.760 And so we were estimating it would be comparable to do this. 23:55.760 --> 24:00.280 And this is what your company does, like data recovery? 24:00.280 --> 24:01.660 Or is it specific to... 24:01.660 --> 24:03.120 Not originally. 24:03.120 --> 24:08.660 Originally, we were working on a distributed operating system. 24:09.980 --> 24:19.240 And we could get clients interested if we can get in the door, but it was right at the time when cryptocurrency was taking off, and we didn't have to talk to anybody to get them in. 24:19.900 --> 24:28.980 We started doing some consulting work there, built up a team of about 20 scholarly developers that were top of the... 24:30.840 --> 24:33.300 cream of the crop, top of their field. 24:33.940 --> 24:39.780 And then built the rChain cryptocurrency platform. 24:40.220 --> 24:42.920 rChain started having some financial troubles. 24:42.920 --> 24:46.560 We allowed them to hire the devs early. 24:46.560 --> 24:52.180 We had a contract that we'd hold on to them for a while, and then they could hire them after they'd worked for us for a year. 24:52.180 --> 24:54.020 But we let them hire them early. 24:54.160 --> 24:56.820 So they've taken over the dev team. 24:56.860 --> 24:59.180 And then we started working on some other things. 24:59.180 --> 25:03.280 And this particular consulting job came up at a nice time. 25:03.280 --> 25:04.540 It was a whole lot of fun. 25:04.540 --> 25:10.240 But right now we're looking for any interesting consulting work that people have. 25:10.240 --> 25:14.900 That was exactly what I wanted to segue into now that you've done this talk. 25:15.300 --> 25:21.460 Do you have another research item on your to-do list that you're trying to aim at? 25:22.220 --> 25:23.100 Sure. 25:23.820 --> 25:30.260 At the moment, I'm doing some consulting work for the Ethereum Foundation. 25:30.260 --> 25:38.140 I've got some consensus algorithm research that I'm working on. 25:38.730 --> 25:48.920 We got access to GPT-3, so we're building an adventure game, kind of like AI Dungeon, but with more structure using GPT-3. 25:49.300 --> 26:02.240 We've got various ideas for voice assistants that will be able to call somebody at a restaurant rather than figure out every different restaurant's online ordering system. 26:02.240 --> 26:06.920 You just have your assistant call them up and have a conversation. 26:07.140 --> 26:11.000 GPT-3 seems to be able to have conversations, so maybe we can use that. 26:11.100 --> 26:17.660 This is probably a really small piece of what you're doing, but I used to be incredibly into MUDs. 26:17.700 --> 26:22.160 So an adventure game that's generated by GPT-3 sounds interesting. 26:22.160 --> 26:28.460 Yeah, so we're working on the room generation for quests. 26:28.460 --> 26:32.100 You have to convince this character to give it to you. 26:32.100 --> 26:34.920 He's got desires and needs. 26:34.920 --> 26:41.580 So you'll have to be role-playing while you're doing this game, interacting with these characters. 26:41.580 --> 26:49.360 There is a person that goes by the handle Evil Mog, is running a DEF CON CTF MUD right now. 26:49.360 --> 26:52.180 Just a shout out to him. 26:52.300 --> 26:54.440 We are really close to being out of time. 26:54.440 --> 26:59.400 There are a lot of questions over here about specific pieces, specific technologies. 26:59.400 --> 27:05.540 I think I'd like for people to bring those to you on a less moderated basis. 27:05.540 --> 27:07.880 So we'll let those go for now. 27:08.060 --> 27:14.920 Before I let you go, I want to know, what is the thing that you would like us to take away from this? 27:14.920 --> 27:20.660 If there is a final idea that we should walk away from your talk. 27:25.260 --> 27:28.020 That attacks on cryptography only get better. 27:29.340 --> 27:37.200 At the time MD5 was proposed, 128 bits for a 64-bit attack was inconceivable. 27:37.200 --> 27:42.020 And yet, within 5 to 10 years, they were able to attack that one. 27:42.020 --> 27:44.700 And then SHA, there are attacks. 27:44.920 --> 27:52.840 AES with the bi-click attack, they've now broken, I think, seven or eight of the 10 rounds. 27:53.140 --> 28:03.540 If there is something that you need to keep secure, choose the best software and have a plan for upgrading your crypto and any products that you put crypto into. 28:03.660 --> 28:05.520 Because the attacks are going to get better. 28:05.520 --> 28:10.260 You'll need at some point to transition from the broken system to a new one. 28:10.980 --> 28:15.360 And so that will come up during the lifetime of your product. 28:15.360 --> 28:17.400 So be thinking about it. 28:17.680 --> 28:19.460 That's definitely good advice. 28:19.460 --> 28:19.740 Yeah. 28:23.880 --> 28:26.440 Falvo, you got any more questions you want to sneak in under the hood? 28:26.880 --> 28:28.120 No, I think I'm good. 28:28.120 --> 28:30.560 I really appreciate the work that you've done here. 28:30.560 --> 28:35.900 And thank you for coming to present and giving your time to this Q&A session. 28:36.420 --> 28:40.880 There are some more people that have some more questions coming in, if you're willing to do so. 28:40.880 --> 28:47.980 If you would put your contact information in the TrackOne channel on Discord here, we will get that out there. 28:47.980 --> 28:52.600 Folks can look you up if you're willing to be available to that. 28:52.600 --> 29:02.060 I also recommend you put all of your company information, if you're willing to do so, because that's a good way for people to find you for those contracts you were talking about. 29:02.440 --> 29:03.000 Great. 29:03.000 --> 29:04.220 Thank you very much. 29:04.220 --> 29:05.020 All right. 29:05.600 --> 29:06.300 Take care.