WEBVTT 00:00.000 --> 00:05.200 Another author of this presentation is Seungjoo Kim. 00:05.260 --> 00:10.340 In this presentation, we prepared together, but only I speak. 00:10.340 --> 00:16.880 The title is Blockchain for Cyber Defense and Will It Be Good As You Think? 00:16.880 --> 00:18.900 is our topic. 00:19.080 --> 00:21.320 It's 5 a.m. 00:21.320 --> 00:27.440 in Korea, so I think the condition is not normal, but I hope you understand. 00:36.920 --> 00:40.340 Again, I'm Seungri Lee, and I'm a Ph.D. 00:40.340 --> 00:42.040 student at Korea University. 00:42.260 --> 00:45.460 I'm the captain of the Republic of Korean Army. 00:45.520 --> 00:50.660 I have three years' experience as a researcher in the Agency for Defense Development. 00:50.660 --> 00:56.580 It's about the development of the defense and armed system. 00:56.940 --> 01:02.120 As a security researcher, I'm interested in network security and cyber defense. 01:03.340 --> 01:17.200 About blockchain, I was a speaker of CryBlock 2019 at IEEE Infocom. 01:17.520 --> 01:22.120 The title was Countering Block Withholding Attack Efficiently. 01:22.240 --> 01:28.540 Also, I will speak at CryBlock 2020 at ACM Mobicom. 01:28.540 --> 01:41.560 It will be September, and the title will be No Prosperous Take Has Taken Predatory Destructive Attack on Prosperous Take Cryptocurrencies. 01:41.560 --> 01:48.760 It will be about a novel attack methodology about POS cryptocurrency. 01:49.760 --> 01:51.600 It's not about research. 01:51.600 --> 01:56.360 I like to get groundbreaking ideas from philosophy. 01:56.360 --> 02:03.180 My favorite philosophers are Derrida, Nietzsche, Foucault, and Wittgenstein. 02:03.180 --> 02:07.980 Another author of this presentation is Seungju Kim. 02:07.980 --> 02:15.460 He's my advisor, and he's a professor of cybersecurity at Korea University. 02:15.460 --> 02:27.680 He's a reviewer in several international hacking conferences like Black Hat Asia and Secure Insight. 02:27.680 --> 02:31.900 He's also an advisor of an undergraduate hacking club, Cyker. 02:32.780 --> 02:38.440 The hacking group Cyker is now competing in DEF CON online. 02:38.440 --> 02:56.640 His main research areas are focused on trustworthy systems, development methodology, secure SDLC, RMAF, common criteria, CMVP, blockchain, etc. 02:58.060 --> 03:02.940 So our topics are, what is blockchain for cyber defense? 03:02.940 --> 03:13.200 Maybe many of you are blockchain professionals but not familiar with cyber defense or blockchain for cyber defense. 03:13.260 --> 03:29.400 Our main discussions are challenges in cyber defense, and then we will talk about related military projection analysis. 03:30.220 --> 03:33.600 As a summary, we will talk about takeaway. 03:40.490 --> 03:44.130 Targets of this talk are four kinds of people. 03:44.650 --> 04:02.530 Someone interested in blockchain, someone interested in cyber defense, and someone interested in how blockchain can be hacked, and someone who needs fresh ideas. 04:04.150 --> 04:07.890 Who doesn't know blockchain or what is cyber defense? 04:07.890 --> 04:15.950 I hope this talk will give you fresh ideas about this topic or any ideas. 04:19.270 --> 04:22.250 So blockchain for cyber defense, what is it? 04:22.250 --> 04:27.170 Maybe you know what is blockchain. 04:27.170 --> 04:33.110 Actually, blockchain is not clearly defined. 04:33.110 --> 04:38.510 Blockchain is started from Bitcoin founded by Satoshi Nakamoto. 04:38.510 --> 04:53.210 In his white paper, he didn't write clear definition of blockchain, but his main topic was Bitcoin. 04:54.450 --> 05:01.310 In my thought, I think blockchain is constructed by three concepts. 05:01.310 --> 05:07.570 Maybe some can think differently because the start of blockchain was not clearly defined. 05:07.570 --> 05:23.910 One is, as a data structure, hash chain blocks, as a network structure, distributed network, and as a consensus structure, decentralized consensus. 05:24.650 --> 05:35.810 And it has some fundamental problems. 05:35.810 --> 05:37.750 It's called trilemma. 05:37.750 --> 05:41.310 Scalability, security, and decentralization. 05:41.310 --> 05:49.410 Three kinds of characteristics can be satisfied at the same time. 05:51.230 --> 05:53.310 Then what is cyber defense? 05:53.310 --> 05:58.930 Maybe some of you know, but maybe majority of you don't know. 05:58.930 --> 06:00.710 This picture is just for fun. 06:00.710 --> 06:02.510 It's not like cyber defense. 06:03.150 --> 06:05.190 It's just funny. 06:07.310 --> 06:09.370 So what is cyber defense? 06:09.370 --> 06:17.330 Before I talk about this, I should define what is cyber security. 06:17.330 --> 06:28.570 Classically, many people talk about information security, but also many people just talk about cyber security like information security. 06:28.570 --> 06:42.510 If cyber security is the same as information security, then it's not worth to talk about cyber security or name cyber security. 06:42.510 --> 06:52.670 So I bring a clear and distinguishable definition from the reference at the bottom you can see. 06:53.130 --> 07:02.230 In their research, they define cyber security as treating stress using ICT. 07:02.230 --> 07:04.550 Then what is classical information security? 07:04.550 --> 07:09.870 Information security is treating stress to information-based assets. 07:09.870 --> 07:15.110 But cyber security is treating any stress using ICT. 07:15.610 --> 07:18.990 ICT is information and communication technology. 07:18.990 --> 07:26.550 For example, car accident is not included in information security. 07:26.550 --> 07:37.690 But if car accident is by a car remotely controlled by a hacker, then it is included in cyber security domain. 07:37.690 --> 07:41.930 Now we can define what is cyber defense. 07:42.830 --> 07:49.410 Cyber defense is intersection of cyber security and national security or national defense. 07:49.410 --> 07:57.830 National security and national defense are used in the same way many times. 07:59.650 --> 08:08.990 Not only cyber defense is about military defense, but widely it's all about national security. 08:09.570 --> 08:11.850 So why is it like that? 08:11.850 --> 08:14.950 You can see in the picture. 08:15.670 --> 08:24.670 At the past, the stress to countries was through only military domain. 08:24.670 --> 08:31.310 They should overcome armed forces, army, air force, and navy. 08:32.610 --> 08:40.270 So general physical stress on defense is through military area. 08:40.270 --> 08:50.930 But non-military domain, including severe assets and critical infrastructures, are covered by military domain. 08:50.930 --> 08:59.030 But these days, they can be attacked directly by ICT, information and communication technologies. 08:59.030 --> 09:14.310 For example, they can hack the plant and hack the financial systems and hack governmental information systems. 09:14.350 --> 09:18.230 It's already happened. 09:18.230 --> 09:23.810 In 2007, cyber attack to Estonia was really severe. 09:23.810 --> 09:28.670 That's the beginning of the CCTCOE in NATO. 09:28.730 --> 09:33.770 In 2010, Stuxnet to Iranian nuclear facilities. 09:33.770 --> 09:45.070 It was shocking accident that computer virus can stop the nuclear targets and stop nuclear plant. 09:45.070 --> 09:53.230 In 2015, Black Energy temporarily stopped the Ukrainian power grid. 09:53.570 --> 10:01.530 Now, cyber attacks can directly attack national security and national assets. 10:01.530 --> 10:06.890 Therefore, national countries need powerful cybersecurity technologies. 10:07.070 --> 10:11.390 That's how cyber defense meets blockchain. 10:12.390 --> 10:16.700 Blockchain looks secure and reliable. 10:17.270 --> 10:27.560 Many articles and news always talk about it's really nice secure world with blockchain. 10:28.010 --> 10:34.210 Secure, reliable, survival, and so on. 10:34.210 --> 10:35.600 It's true. 10:35.600 --> 10:47.980 Blockchain technology is not about single point of failure and it's immune to any minority attacks. 10:47.980 --> 10:53.800 Even DDoS attacks are really difficult to blockchain. 10:53.800 --> 10:57.060 It should overcome majority resources. 10:59.820 --> 11:07.240 So, policy makers of countries easily think like that. 11:07.240 --> 11:15.880 Defense systems require high security and high reliability. 11:15.880 --> 11:19.420 Blockchain looks unhackable. 11:19.420 --> 11:22.980 Okay, then defense needs this technology. 11:22.980 --> 11:26.680 It's really simple logic and expectable. 11:27.840 --> 11:33.800 In reality, many projects are already in progress. 11:34.600 --> 11:42.120 We will discuss about related projects in the next section. 11:42.120 --> 11:47.500 But in preview, military-included messaging app built on blockchain. 11:47.500 --> 11:55.060 Blockchain supply chain enhancement for trusted and assured FPGA and ASICs. 11:55.060 --> 11:58.480 Decentralized key management using blockchain. 11:58.480 --> 12:04.260 Army innovation network provenance using blockchain and disconnected networks. 12:04.260 --> 12:07.140 Navy multi-factor authentication. 12:07.760 --> 12:10.820 Coups through resilient blockchain framework. 12:10.820 --> 12:14.140 Chinese soldiers reward system using cryptocurrency. 12:14.760 --> 12:18.340 Blockchain-based record intelligence. 12:18.540 --> 12:21.720 French military police record on Tazos blockchain. 12:21.720 --> 12:23.160 South Korean military. 12:23.160 --> 12:28.500 Blockchain-based digital identification, DID. 12:28.500 --> 12:31.520 And also other projects. 12:31.740 --> 12:36.480 So, will it be as good as you think? 12:36.480 --> 12:43.300 Well, in this talk, I want to question and introduce some challenges. 12:45.300 --> 12:50.400 So, to meet the challenges, let's go to the battleground. 12:51.660 --> 12:54.700 Maybe some of you like this game. 12:55.840 --> 12:59.660 So, what is waiting for us in the battleground? 13:00.880 --> 13:03.440 There is a profession. 13:03.720 --> 13:07.420 I introduced a profession, Carl von Clausewitz. 13:07.440 --> 13:12.300 And he is a really professional in war and battleground. 13:12.300 --> 13:16.800 He said in Twitter, war is a volume of uncertainty. 13:16.800 --> 13:27.180 Three quarters of the factors on which action in war is based are wrapped in a fog of greater and lesser uncertainty. 13:27.900 --> 13:32.460 In summary, he says, it's full of uncertainty. 13:32.460 --> 13:35.260 So, what is big uncertainty? 13:35.260 --> 13:43.980 Blockchain technology already assumes many uncertain situations, right? 13:43.980 --> 13:50.440 But in battleground, uncertainty can be really extreme. 13:50.440 --> 13:58.000 For example, you got ordered to go to mountain and save the mountains. 13:58.000 --> 14:01.220 In Korea, mountains are like that. 14:01.460 --> 14:10.820 And our territory is covered by mountains like that. 14:10.820 --> 14:20.200 So, when you got ordered to go to mountain, then we expect mountains are covered by trees, usually, right? 14:20.260 --> 14:25.040 But in reality, mountains can be devastated. 14:26.960 --> 14:33.200 You can go to mountain and there can be even no single tree. 14:33.260 --> 14:36.740 Rare trees burned down a year ago. 14:36.740 --> 14:43.620 In Korean war in 1950, most of our trees burned down. 14:44.340 --> 14:55.560 So, what I want to say is situations in battleground can be extremely miserable. 14:56.680 --> 15:04.800 But you got ordered and you should say, I swear in army. 15:06.580 --> 15:14.680 So, let's assume policy makers said adopt the blockchain technology and secure our networks. 15:16.100 --> 15:19.880 Also, let's assume it's not questionable. 15:19.880 --> 15:24.340 You are not allowed to question about this decision. 15:25.340 --> 15:37.640 Actually, many people don't agree with private blockchain networks. 15:40.000 --> 15:43.420 So, we will encounter three challenges. 15:43.420 --> 15:45.800 Challenge one, air gap networks. 15:45.800 --> 15:49.720 And challenge two, first dynamic environment. 15:50.240 --> 15:54.240 And challenge three, the resource shortage. 15:55.220 --> 15:58.480 So, challenge one, air gap networks. 15:58.480 --> 16:00.100 So, what is air gap networks? 16:00.400 --> 16:04.400 This is maybe familiar for most of you. 16:04.900 --> 16:18.940 In military networks and critical infrastructures in most countries, many networks have air gap environments. 16:20.200 --> 16:26.880 Air gap is something technology to make networks isolated. 16:26.880 --> 16:35.620 So, you can see internet, mainly stressors come from outer internet. 16:35.620 --> 16:41.160 So, to protect internet, you can make air gaps. 16:41.160 --> 16:47.540 Air gaps can be software-based air gap and hardware-based air gap. 16:47.540 --> 16:50.080 And there is true air gap. 16:50.080 --> 16:54.520 True air gap means there is no communication between air gap. 16:54.520 --> 16:58.380 But, well, it's not always magical. 16:58.380 --> 17:03.220 Because Stuxnet exploded air gap networks. 17:03.220 --> 17:14.120 Anyway , if there is an air gap, then it is hard to construct blockchain. 17:14.120 --> 17:23.740 Because communication is not possible and many networks are partitioned and isolated. 17:23.740 --> 17:28.880 So, anyway, let's make blockchain here. 17:29.260 --> 17:44.760 So , for example, you can construct servers of each isolated network and communicate messages by those servers. 17:44.760 --> 17:50.040 Then, it will be a single point of failure and it's just centralized. 17:51.040 --> 18:02.940 Another way, you can make isolated networks and each isolated network has isolated blockchain. 18:02.940 --> 18:15.440 But isolated networks have not enough nodes or servers to make enough decentralized networks. 18:15.440 --> 18:20.940 So, it will make decentralization not effective. 18:21.860 --> 18:30.420 So, in summary, because of the air gap structure of defense network, it may be hard to adopt blockchain. 18:31.700 --> 18:36.560 And second challenge, first dynamic environment. 18:38.400 --> 18:44.580 Wherever the military goes, communication must always exist. 18:46.260 --> 19:05.300 Actually, it was same as the past warfare, but in modern warfare, getting information and process the information and make decisions are really important and should be fast. 19:05.300 --> 19:13.080 Because we should make decisions faster than enemy and move faster than enemy. 19:14.580 --> 19:20.480 So that we can make the superior position. 19:20.480 --> 19:33.080 So, anyway, for this process, communication must be followed. 19:33.080 --> 19:44.560 So, in this picture, in modern warfare, all of these things require communication. 19:44.560 --> 19:50.640 So, it means, let's see the example. 19:53.300 --> 20:10.980 It's map of World War II and second map is how Nazi extended their occupied territory really fast and broadly. 20:10.980 --> 20:17.340 And right map is how their occupied territory shrinked really fast. 20:18.080 --> 20:22.380 Let's see the left map. 20:22.820 --> 20:37.240 When Nazi extended their occupied territory, then communication system must follow all of occupied territory and cover their communication really fast. 20:41.160 --> 20:48.860 Even if their advance is really fast, communication and their system must follow. 20:48.860 --> 20:50.720 There's no exception. 20:50.720 --> 21:08.240 At the right map, even if their occupied territory shrinks really fast, communication system will shrink really fast. 21:08.240 --> 21:12.240 Anyway , just whatever is distributed throughout. 21:13.120 --> 21:14.960 Another example. 21:14.960 --> 21:17.040 It's our country case. 21:17.040 --> 21:21.700 It's map of Korean War in 1950. 21:22.960 --> 21:33.480 Before the Korean War, the territory was divided at this line, 38th parallel. 21:33.480 --> 21:42.480 In three months, South Korea's territory was shrinked to just two cities, Daegu and Busan. 21:42.600 --> 21:45.640 And we are really shrinking really fast. 21:45.640 --> 21:57.880 But you can see, just in two or three months, we expanded our territory till the nearly end of North Korea. 21:57.880 --> 22:02.200 But we retreated really fast again. 22:02.200 --> 22:20.050 So, what I want to say is, better ground environment is really dynamic and we can't choose and there's no exception. 22:20.130 --> 22:27.250 We are just first to meet situations. 22:27.370 --> 22:34.110 So, let's move on the blockchain. 22:34.110 --> 22:39.530 So, let's consider the case, sudden expansion. 22:41.110 --> 22:47.030 Our private blockchain network is just like PBFT. 22:48.510 --> 22:57.970 At the left situation, we have 8 total nodes and acceptable 30 nodes are like 2. 22:57.970 --> 23:15.370 But we expanded our territory really fast and we just added a lot of nodes because we should cover the occupied territory. 23:15.370 --> 23:19.530 Then, acceptable 30 nodes should be 12. 23:19.530 --> 23:28.650 But in PBFT, this kind of consensus mechanism, we need settings. 23:29.030 --> 23:42.590 But if this expansion is really fast and if this setting is not adapted, then it will be really easy to make consensus. 23:42.590 --> 23:46.270 So, past majority becomes minority. 23:46.270 --> 23:52.850 8 is minority of 36, so that is now your minority can make consensus. 23:53.590 --> 23:57.230 Another case is kind of a reverse case. 23:57.230 --> 23:59.790 So , let's think about sudden sharing key. 24:00.470 --> 24:02.890 Sharing key is this typo. 24:04.690 --> 24:18.950 Your original set is total nodes 36 and in PBFT, the number of acceptable 30 nodes is 11. 24:19.010 --> 24:23.710 But most of nodes are just destroyed. 24:23.710 --> 24:30.750 And then you have total nodes 8 and the number of acceptable 30 nodes should be 3. 24:30.750 --> 24:37.750 But you are just destroyed, so you can't make setting in the time. 24:37.750 --> 24:42.150 So, it will be nearly impossible to make consensus. 24:42.610 --> 24:50.730 So , the past minority becomes the majority in this situation. 24:50.730 --> 24:54.570 That is, now your majority can't make the consensus. 24:56.690 --> 25:00.750 So, another situation, bombing and partitioning. 25:00.750 --> 25:03.200 It's the last situation. 25:03.450 --> 25:07.890 Your nodes just can't be partitioned. 25:07.890 --> 25:19.650 In public blockchain, it's nearly impossible because nodes are connected by a worldwide web. 25:19.650 --> 25:24.220 So, it's really hard to make clear partition. 25:24.490 --> 25:27.250 Just divide into two partitions. 25:27.250 --> 25:33.690 But it's possible in VR situations. 25:33.690 --> 25:41.350 So , for example, you have to turn 36 nodes and partition them. 25:41.410 --> 25:44.210 There's no majority anymore. 25:44.970 --> 25:47.210 Furthermore, there's another issue. 25:47.210 --> 26:07.290 If you connect the partitions but they have their own blocks, especially for PVF tier deterministic consensus mechanisms, consistency will be a really big problem. 26:07.290 --> 26:10.550 So, we'll meet our first problem. 26:10.550 --> 26:17.810 In military situation, we can't just throw another information. 26:17.810 --> 26:21.450 We can't choose just one information. 26:21.450 --> 26:26.670 We need to collect all information and process and decide. 26:26.670 --> 26:28.790 So, it'll be a problem. 26:29.510 --> 26:31.750 So, it was the second challenge. 26:31.790 --> 26:39.270 To summarize, in more extreme situations, assumptions can be easily broken. 26:39.270 --> 26:43.370 Weakness can be easily revealed. 26:43.370 --> 26:56.530 So , especially in my examples, deterministic consensus mechanisms that cannot guarantee aliveness are real problems in these situations. 26:58.270 --> 27:00.410 Challenge 3, research shortage. 27:00.410 --> 27:04.730 Actually, it's a classical problem of blockchain. 27:05.730 --> 27:13.630 But I can't mention this problem. 27:13.630 --> 27:19.610 Blockchain's other name is state replication system. 27:19.610 --> 27:29.290 So, it'll replicate computation resource, storage resource, latency resource, bandwidth resource. 27:29.960 --> 27:40.790 But existing military system were considered existing missions and existing systems. 27:40.790 --> 27:49.920 So, just replicating existing performances will be a problem. 27:50.350 --> 27:58.750 And we adopt blockchain for missions, not missions for blockchain. 27:58.750 --> 28:03.330 So, influence on mission-critical functions should be checked. 28:03.330 --> 28:08.870 Mission-critical functions should be guaranteed and then we can adopt blockchain. 28:09.250 --> 28:13.030 But, yeah, first problem is resource consumption. 28:13.030 --> 28:14.490 Then, what is second problem? 28:14.490 --> 28:20.050 Second problem is serving resource consumption is not easy. 28:20.050 --> 28:34.870 So, if we don't have enough resources, then we should get more resources and then we need to get more systems or more resources. 28:34.870 --> 28:43.210 Then, we need to use defense acquisition process. 28:46.270 --> 29:05.670 But maybe some of you already knew that military acquisition process is really conservative and it requires really rigorous tasks and evaluation process. 29:05.670 --> 29:07.830 It's really heavy. 29:10.290 --> 29:17.610 Defense acquisition process was having developed in this way. 29:17.610 --> 29:31.950 So , you can see in the left picture, it's the US military acquisition system and it's really bureaucratic and conservative and really heavy. 29:31.950 --> 29:47.330 So, there are many articles and interviews that DOD or many countries are suffering from full defense acquisition process. 29:50.030 --> 30:00.930 Well, rigorous tasks and evaluations and rigorous acquisition system process is essential. 30:00.930 --> 30:14.710 But, it is a really big problem in cybersecurity because, you know, system is developed and vulnerabilities are always hiding. 30:16.990 --> 30:30.790 Vulnerabilities are just found time by time, but military acquisition system is not that rapid to react from these updates or kind of that. 30:30.790 --> 30:45.790 So, anyway, military bureaucratic acquisition system process, because of that, it will be difficult to solve resource consumption problem. 30:47.090 --> 30:50.450 So, in this situation, what can you do? 30:50.450 --> 30:56.970 To adopt proof-of-work, we can't waste energy. 30:56.970 --> 31:04.550 Of course, proof-of-stake, we don't have coins in defense system. 31:04.550 --> 31:16.510 And when we go to private consensus mechanism like PVRT, then we will go back to the challenge 2 again. 31:16.510 --> 31:22.490 It can't guarantee liveness, so it will make such extreme problems. 31:24.390 --> 31:35.910 So, in summary, mission is always first, but due to the military environment, support is not so timely and sufficient to adopt blockchain. 31:37.110 --> 31:41.840 So, next is related military projects. 31:42.050 --> 31:51.430 So, we surveyed 42 defense projects about blockchain and categorized as below. 31:51.430 --> 31:57.570 And each project can be categorized into multiple categories. 31:57.570 --> 32:09.090 For example, there's a research about key management about military drone system. 32:09.090 --> 32:16.330 Then it's categorized into internet of things and communications and identification and authentication. 32:16.990 --> 32:25.990 And especially data integrity category is just for data integrity project. 32:25.990 --> 32:34.710 It's because adopting blockchain technology is basically about data integrity. 32:34.970 --> 32:44.170 So, we categorized a project only about data integrity into that category. 32:44.170 --> 32:47.470 So, main categories are like that. 32:47.470 --> 32:57.640 Data integrity, supply chain management, internet of things and communications, and identification and authentication. 32:57.640 --> 33:18.440 So, we are somewhat careful about mentioning a project because about related project, detailed information about many real military projects are classified. 33:18.440 --> 33:28.740 We got information from project notification, interviews, and news articles. 33:28.740 --> 33:40.000 So, the information we got can be not clear or can be somewhat misunderstood. 33:40.200 --> 33:48.380 So, we want to notice that our comments are based on limited information. 33:50.040 --> 33:53.140 So, data integrity. 33:55.340 --> 33:58.680 For example, there are three projects. 33:58.860 --> 34:04.000 French military police records on Taz's blockchain. 34:04.000 --> 34:08.280 It's interesting that they put records on public blockchain. 34:08.680 --> 34:18.020 So, maybe they can avoid problems that I mentioned like the problems happening in private blockchain. 34:18.020 --> 34:20.720 And another example is U.S. 34:20.720 --> 34:28.360 DoD project sharing of defense research development testing evaluation on blockchain. 34:29.540 --> 34:34.440 And another project is also U.S. 34:34.440 --> 34:38.000 DoD provenance using blockchain on disconnected networks. 34:38.000 --> 34:48.400 This project is also interesting that they already considered some disconnected network situation in tactical networks. 34:51.770 --> 34:57.530 So, another related category is supply chain management. 34:57.790 --> 35:06.880 In cyber defense, supply chain management is really a big issue. 35:06.880 --> 35:18.140 Maybe you read Bloomberg article about microchip hacking. 35:18.320 --> 35:27.440 I don't know if it's true or not, but what I know is it was truly a big issue. 35:28.020 --> 35:34.760 And there are other articles about supply chain attacks are suspicious. 35:34.760 --> 35:41.220 Yeah, it's truly a really big, really important attack factor. 35:41.220 --> 35:43.260 And so, there's a U.S. 35:43.260 --> 35:51.600 DoD project about it, blockchain supply chain enhancements for trusted and assured LPGA and ASICs. 35:51.600 --> 36:02.580 But blockchain on supply management is actively researched for efficiency about supply chain, not only for security. 36:03.580 --> 36:07.640 Another category is Internet of Things. 36:08.960 --> 36:11.480 There's a U.S. 36:11.480 --> 36:21.560 Department of Homeland Security project combining blockchain technology with critical infrastructure. 36:21.560 --> 36:34.950 This project is about sensors and cameras that protect integrity and authenticity of critical infrastructure. 36:34.950 --> 36:46.530 This project is about IoT, so we can just relate it to Challenge 3 research series. 36:46.530 --> 36:57.450 But I think the infrastructure is not dynamic, so it can be adaptable, I think. 36:58.450 --> 37:10.630 So, in communication category, there's a DARPA project building an encrypted message system based on blockchain technology. 37:13.110 --> 37:25.370 I think it's about tactical networks, so I don't know the detailed information, but if it is related to messages in tactical networks. 37:25.370 --> 37:31.130 Challenge 2, first dynamic environments, and Challenge 3 research series should be considered. 37:31.130 --> 37:33.310 Maybe they will be considered. 37:34.570 --> 37:42.430 For identification and authentication, there are two projects. 37:42.430 --> 37:44.470 For example, a U.S. 37:44.470 --> 37:48.870 DHS project decentralizes KME management using blockchain. 37:48.870 --> 37:53.590 There's a South Korea project 37:57.070 --> 38:01.030 blockchain -based DID. 38:01.030 --> 38:11.930 But maybe some of you noticed, some of these projects are not domain-specific. 38:11.930 --> 38:16.550 I mean, it's not just only for cyber defense. 38:16.550 --> 38:20.570 Many projects are just general. 38:20.570 --> 38:34.190 But for this project, especially identification and authentication, the decentralized key management and DID is not only military issue, not only cyber defense. 38:34.190 --> 38:37.610 So maybe they are not interesting. 38:38.170 --> 38:45.070 So, related projects in my examples are like that. 38:45.070 --> 38:52.530 Lines mean that projects are not domain-specific. 38:54.210 --> 39:04.470 I'm interested in blockchain specifically for cyber defense. 39:04.470 --> 39:10.530 So I'm still surveying about this topic and I'm preparing a paper. 39:13.140 --> 39:21.580 Actually, I think I criticized a lot with just question this topic and introduced challenges. 39:21.580 --> 39:25.580 But then some can ask, then what are alternatives? 39:26.280 --> 39:32.280 What I want to say is we don't need to choose a perfect blockchain structure. 39:32.280 --> 39:45.720 As I mentioned at the first part of this talk, blockchain is constructed by three concepts. 39:45.760 --> 39:48.580 As a data structure, hash chain blocks. 39:48.580 --> 39:52.040 And as a network structure, distributed network. 39:52.040 --> 39:56.020 And as a consensus structure, decentralized consensus. 39:56.020 --> 40:01.140 But you can just give up one concept or two concepts. 40:01.140 --> 40:07.940 Maybe you only need distributed network and penalized networks. 40:07.940 --> 40:18.220 So what I need to do is figure out problems and figure out right solutions. 40:18.220 --> 40:27.300 Not just decide to use blockchain and figure out which blockchain is adaptable. 40:28.800 --> 40:35.520 So to summarize, takeaway are three. 40:35.520 --> 40:41.700 Cyber defense makes more challenges and requirements for blockchain. 40:41.820 --> 40:45.820 Error gaps, sudden expansion, shrinkage, partitioning. 40:46.680 --> 40:49.860 Extreme situation can exist. 40:51.700 --> 40:57.460 Second, blockchain's resource consumption can be a problem. 40:57.460 --> 41:04.020 But defense environments are not that flexible to assign more resources. 41:05.980 --> 41:11.880 Third, we don't need to cling to blockchain if it's not adaptable. 41:11.880 --> 41:15.320 Otherwise, it will bring more issues. 41:15.320 --> 41:19.220 So it's all of my talk. 41:19.360 --> 41:22.920 And get in touch to these emails. 41:22.920 --> 41:26.780 We welcome any questions and discussions. 41:27.000 --> 41:37.650 And I think this presentation will be uploaded somewhere so you can see our emails. 41:38.650 --> 41:46.250 So thank you for your attention and thank you again. 41:46.250 --> 41:47.650 Any questions? 42:27.170 --> 42:29.370 Is there a question? 42:41.810 --> 42:48.210 If you can't ask now, then you can just send email or send message to Discord. 42:48.840 --> 42:53.340 Any questions and discussions are welcome. 43:04.070 --> 43:05.490 Okay, then. 43:05.490 --> 43:06.910 Thank you. 43:06.910 --> 43:12.430 Then I can just quit the live streaming, right?