1 1 00:00:00,300 --> 00:00:02,010 Root of trust. 2 2 00:00:02,010 --> 00:00:02,940 In this lesson, 3 3 00:00:02,940 --> 00:00:04,470 we are going to talk about the concept 4 4 00:00:04,470 --> 00:00:07,440 of a hardware root of trust or ROT. 5 5 00:00:07,440 --> 00:00:09,270 Now, this is a cryptographic module 6 6 00:00:09,270 --> 00:00:11,130 embedded within a computer system 7 7 00:00:11,130 --> 00:00:12,870 that can endorse trusted execution 8 8 00:00:12,870 --> 00:00:15,330 and attest to boot settings and metrics. 9 9 00:00:15,330 --> 00:00:17,460 Now, this may sound like a complicated concept 10 10 00:00:17,460 --> 00:00:19,950 but you use a root of trust all the time. 11 11 00:00:19,950 --> 00:00:21,840 If you think about your TPM module 12 12 00:00:21,840 --> 00:00:22,710 inside your bios, 13 13 00:00:22,710 --> 00:00:24,330 that is a root of trust. 14 14 00:00:24,330 --> 00:00:25,860 Essentially, a root of trust 15 15 00:00:25,860 --> 00:00:28,080 is used to scan the boot metrics of the system 16 16 00:00:28,080 --> 00:00:29,550 and the operating system files 17 17 00:00:29,550 --> 00:00:31,080 and it verifies their signatures. 18 18 00:00:31,080 --> 00:00:33,090 And then we can use that root of trust 19 19 00:00:33,090 --> 00:00:34,680 to sign a digital report, 20 20 00:00:34,680 --> 00:00:36,517 to send that over to the processor and say, 21 21 00:00:36,517 --> 00:00:37,890 "I trust these things." 22 22 00:00:37,890 --> 00:00:39,930 Essentially, it's a digital certificate, 23 23 00:00:39,930 --> 00:00:41,730 but it's embedded inside your processor 24 24 00:00:41,730 --> 00:00:43,320 or inside your firmware. 25 25 00:00:43,320 --> 00:00:44,490 Now, as I mentioned earlier, 26 26 00:00:44,490 --> 00:00:46,050 the most common root of trust 27 27 00:00:46,050 --> 00:00:49,320 is a trusted platform module or TPM. 28 28 00:00:49,320 --> 00:00:50,490 This is a specification 29 29 00:00:50,490 --> 00:00:51,630 for hardware based storage 30 30 00:00:51,630 --> 00:00:52,890 of digital certificates, 31 31 00:00:52,890 --> 00:00:53,723 keys, 32 32 00:00:53,723 --> 00:00:54,690 hash passwords 33 33 00:00:54,690 --> 00:00:57,690 and other user and platform identification information. 34 34 00:00:57,690 --> 00:00:59,820 Now, as you look inside of a TPM, 35 35 00:00:59,820 --> 00:01:02,550 there are lots of different functions inside of it. 36 36 00:01:02,550 --> 00:01:03,720 First, it's going to provide you 37 37 00:01:03,720 --> 00:01:05,610 with secured input and output. 38 38 00:01:05,610 --> 00:01:08,100 Then we have this cryptographic processor 39 39 00:01:08,100 --> 00:01:10,530 that provides us with a true random number generator. 40 40 00:01:10,530 --> 00:01:12,180 It has an RSA key generator, 41 41 00:01:12,180 --> 00:01:14,040 it has a SHA-1 hash generator 42 42 00:01:14,040 --> 00:01:16,800 and encryption decryption signature engines. 43 43 00:01:16,800 --> 00:01:17,633 In addition to that, 44 44 00:01:17,633 --> 00:01:19,260 we also have persistent memory 45 45 00:01:19,260 --> 00:01:20,093 and inside of that, 46 46 00:01:20,093 --> 00:01:20,970 we have an endorsement key 47 47 00:01:20,970 --> 00:01:22,020 which is a digital key 48 48 00:01:22,020 --> 00:01:24,540 and a storage root key or an SRK. 49 49 00:01:24,540 --> 00:01:26,280 And then we have versatile memory. 50 50 00:01:26,280 --> 00:01:27,270 This includes things like 51 51 00:01:27,270 --> 00:01:30,180 platform configuration registers or PCRs, 52 52 00:01:30,180 --> 00:01:32,580 attestation identity keys or AIKs 53 53 00:01:32,580 --> 00:01:33,990 and storage keys. 54 54 00:01:33,990 --> 00:01:35,100 Now, do you have to memorize 55 55 00:01:35,100 --> 00:01:36,210 all of these different things 56 56 00:01:36,210 --> 00:01:37,770 on this chart for TPM, 57 57 00:01:37,770 --> 00:01:38,790 for the exam? 58 58 00:01:38,790 --> 00:01:39,930 Well, not really. 59 59 00:01:39,930 --> 00:01:41,370 Instead, you really need to remember 60 60 00:01:41,370 --> 00:01:42,203 that TPM, 61 61 00:01:42,203 --> 00:01:43,920 the trusted platform module 62 62 00:01:43,920 --> 00:01:45,900 is this part of your system 63 63 00:01:45,900 --> 00:01:47,640 that allows you to have the ability 64 64 00:01:47,640 --> 00:01:49,380 to ensure that when you're booting up, 65 65 00:01:49,380 --> 00:01:50,610 it is done securely. 66 66 00:01:50,610 --> 00:01:51,810 And we could take those reports 67 67 00:01:51,810 --> 00:01:54,180 and digitally sign them using the TPM. 68 68 00:01:54,180 --> 00:01:56,490 TPM is also used with full disk encryption. 69 69 00:01:56,490 --> 00:01:57,323 So if you're using something 70 70 00:01:57,323 --> 00:01:58,770 like BitLocker in Windows, 71 71 00:01:58,770 --> 00:02:02,040 it uses TPM and that key inside of TPM 72 72 00:02:02,040 --> 00:02:04,320 to make sure that data is secure. 73 73 00:02:04,320 --> 00:02:05,820 Now, when you're dealing with TPM 74 74 00:02:05,820 --> 00:02:08,520 your TPM can be managed inside of Windows 75 75 00:02:08,520 --> 00:02:10,830 using tpm.msc, 76 76 00:02:10,830 --> 00:02:11,970 which is a console 77 77 00:02:11,970 --> 00:02:13,950 or you could do it through group policy. 78 78 00:02:13,950 --> 00:02:16,800 Either these are ways you can configure TPM. 79 79 00:02:16,800 --> 00:02:18,030 Now for the exam, 80 80 00:02:18,030 --> 00:02:19,230 you don't need to go in depth 81 81 00:02:19,230 --> 00:02:20,700 of how to configure these things. 82 82 00:02:20,700 --> 00:02:21,660 In the real world, 83 83 00:02:21,660 --> 00:02:23,040 you may be asked to work on this, 84 84 00:02:23,040 --> 00:02:23,873 and if so 85 85 00:02:23,873 --> 00:02:25,020 you could look up the documentation 86 86 00:02:25,020 --> 00:02:27,030 at microsoft.com. 87 87 00:02:27,030 --> 00:02:27,863 Now, the other thing 88 88 00:02:27,863 --> 00:02:28,696 we need to talk about here 89 89 00:02:28,696 --> 00:02:30,630 is a hardware security module. 90 90 00:02:30,630 --> 00:02:31,463 This is an appliance 91 91 00:02:31,463 --> 00:02:33,690 for generating and storing cryptographic keys 92 92 00:02:33,690 --> 00:02:35,370 that is less susceptible to tampering 93 93 00:02:35,370 --> 00:02:38,520 and insider threats than using storage-based solutions. 94 94 00:02:38,520 --> 00:02:40,560 So typically when we do encryption, 95 95 00:02:40,560 --> 00:02:43,890 we do that using some sort of a long key, right? 96 96 00:02:43,890 --> 00:02:45,660 And so I might type in a long password 97 97 00:02:45,660 --> 00:02:47,430 and that becomes my key. 98 98 00:02:47,430 --> 00:02:48,810 Well, the problem with that is 99 99 00:02:48,810 --> 00:02:51,150 it's a lot easier to crack those things 100 100 00:02:51,150 --> 00:02:54,060 because that key could be compromised by an insider 101 101 00:02:54,060 --> 00:02:55,740 or by somebody telling somebody else it 102 102 00:02:55,740 --> 00:02:56,700 or typing it in 103 103 00:02:56,700 --> 00:02:57,930 or something of that nature. 104 104 00:02:57,930 --> 00:02:59,310 Now, there are lots of different ways 105 105 00:02:59,310 --> 00:03:00,660 to create an HSM. 106 106 00:03:00,660 --> 00:03:02,730 They come in lots of different form factors. 107 107 00:03:02,730 --> 00:03:04,020 For example, here on the screen 108 108 00:03:04,020 --> 00:03:05,040 you could see N-cipher 109 109 00:03:05,040 --> 00:03:06,390 and there's three different models. 110 110 00:03:06,390 --> 00:03:07,770 We have one that's an internal card 111 111 00:03:07,770 --> 00:03:08,610 that could be put in. 112 112 00:03:08,610 --> 00:03:10,320 There's one that is a rack mounted system 113 113 00:03:10,320 --> 00:03:11,190 and then there's one that's more 114 114 00:03:11,190 --> 00:03:13,050 of an internet of things type of solution. 115 115 00:03:13,050 --> 00:03:15,090 The real advantage of these types of systems 116 116 00:03:15,090 --> 00:03:16,500 is that they are automated, 117 117 00:03:16,500 --> 00:03:18,510 and that means the keys cannot be compromised 118 118 00:03:18,510 --> 00:03:19,440 by human involvement. 119 119 00:03:19,440 --> 00:03:21,570 So we're removing the person from the equation 120 120 00:03:21,570 --> 00:03:24,060 and ensuring the systems are secure. 121 121 00:03:24,060 --> 00:03:25,470 Now, another thing we need to think about 122 122 00:03:25,470 --> 00:03:26,430 is how do we make sure 123 123 00:03:26,430 --> 00:03:28,650 people can't tamper with our different devices? 124 124 00:03:28,650 --> 00:03:30,810 Well, that's where the concept of anti-tamper 125 125 00:03:30,810 --> 00:03:31,950 comes into play. 126 126 00:03:31,950 --> 00:03:33,510 These are methods that make it difficult 127 127 00:03:33,510 --> 00:03:34,343 for an attacker 128 128 00:03:34,343 --> 00:03:37,290 to alter the authorized execution of software. 129 129 00:03:37,290 --> 00:03:38,670 Now, if you think about anti-tampering 130 130 00:03:38,670 --> 00:03:40,080 and you think about it in the physical world, 131 131 00:03:40,080 --> 00:03:41,610 you buy a thing of aspirin 132 132 00:03:41,610 --> 00:03:42,690 and you open up the bottle, 133 133 00:03:42,690 --> 00:03:44,010 what do you see on top? 134 134 00:03:44,010 --> 00:03:45,487 That sealed layer that says, 135 135 00:03:45,487 --> 00:03:46,560 "This has been protected." 136 136 00:03:46,560 --> 00:03:48,690 This is a sealed for your protection. 137 137 00:03:48,690 --> 00:03:50,280 This is an anti-tampered device 138 138 00:03:50,280 --> 00:03:51,690 because if you pull that seal off, 139 139 00:03:51,690 --> 00:03:53,160 you can't put it back on. 140 140 00:03:53,160 --> 00:03:54,060 And so this shows you 141 141 00:03:54,060 --> 00:03:55,500 that somebody has either been in the bottle 142 142 00:03:55,500 --> 00:03:57,060 or not been in the bottle. 143 143 00:03:57,060 --> 00:03:58,290 Well, we want to do the same thing 144 144 00:03:58,290 --> 00:03:59,640 within our electronics 145 145 00:03:59,640 --> 00:04:01,530 and there are two main ways of doing that. 146 146 00:04:01,530 --> 00:04:03,000 We have anti-tamper mechanisms 147 147 00:04:03,000 --> 00:04:04,860 that include things like an FPGA, 148 148 00:04:04,860 --> 00:04:06,960 which is a field programmable gate array 149 149 00:04:06,960 --> 00:04:10,830 or a physically unclonable function, or PUF. 150 150 00:04:10,830 --> 00:04:12,810 Both of these are anti-tamper mechanisms 151 151 00:04:12,810 --> 00:04:13,650 that could be used 152 152 00:04:13,650 --> 00:04:15,540 and designed inside your systems. 153 153 00:04:15,540 --> 00:04:16,373 This means that 154 154 00:04:16,373 --> 00:04:18,300 if somebody tries to tamper with the system, 155 155 00:04:18,300 --> 00:04:19,380 what these things will do, 156 156 00:04:19,380 --> 00:04:21,600 is actually zero out your cryptographic key 157 157 00:04:21,600 --> 00:04:23,280 which then can automatically 158 158 00:04:23,280 --> 00:04:25,170 wipe out the information on that system, 159 159 00:04:25,170 --> 00:04:27,480 making sure you know it's been tampered with 160 160 00:04:27,480 --> 00:04:30,120 and, therefore, nobody can get the information. 161 161 00:04:30,120 --> 00:04:30,953 That's the idea. 162 162 00:04:30,953 --> 00:04:32,940 When you start using things like anti-tamper.