1 00:00:00,000 --> 00:00:04,520 Cloudflare handles over five trillion web page requests every day, 2 00:00:04,520 --> 00:00:09,520 most of which are encrypted to protect your data. But did you know that this encryption depends on 3 00:00:10,380 --> 00:00:14,120 lava lamps? I'm talking regular lava lamps, 4 00:00:14,120 --> 00:00:19,080 like you can get on Amazon, what? Does the lava have some kind of super secret 5 00:00:19,080 --> 00:00:22,520 processing capability that's soon to put AMD and Intel out of business? 6 00:00:22,520 --> 00:00:25,920 Obviously not, but the lava is a great source 7 00:00:25,920 --> 00:00:29,280 of natural entropy, which is a measure of disorder, 8 00:00:29,360 --> 00:00:33,440 if you think back to high school physics. The reason natural entropy is important 9 00:00:33,440 --> 00:00:38,240 is that it provides natural randomness, which can be used to encrypt data. 10 00:00:38,240 --> 00:00:42,400 You see, the lava inside a lava lamp, which is actually just wax, 11 00:00:42,400 --> 00:00:45,840 flows in naturally random unpredictable patterns 12 00:00:45,840 --> 00:00:49,840 once the lamp is heated, just like how you can't predict exactly how steam 13 00:00:49,840 --> 00:00:54,400 rises from a boiling pot, for example. A camera at Cloudflare's headquarters 14 00:00:54,400 --> 00:00:57,540 is pointed at a wall of approximately 100 lava lamps 15 00:00:57,580 --> 00:01:02,660 and takes a photo ever so often to capture the exact pattern the lava lamps are showing. 16 00:01:02,660 --> 00:01:06,900 Those photos are then sent to a computer that gives each pixel a numerical value 17 00:01:06,900 --> 00:01:11,300 depending on its appearance, creating a random numerical string 18 00:01:11,300 --> 00:01:14,500 that becomes what we call a cryptographic seed. 19 00:01:14,500 --> 00:01:17,700 This seed number is fed into a mathematical function 20 00:01:17,700 --> 00:01:22,700 that creates another seed, which then gets fed into a number generator whose outputs 21 00:01:22,700 --> 00:01:27,420 can be used for cryptographic keys, used to encrypt and decrypt traffic, 22 00:01:27,420 --> 00:01:31,300 making it difficult for attackers to see what you're looking at. 23 00:01:31,300 --> 00:01:35,180 These keys are also used to confirm that the communication actually came 24 00:01:35,180 --> 00:01:39,420 from the website you're connected to, preventing your data from flowing to an attacker 25 00:01:39,420 --> 00:01:42,520 that's pretending to be a legitimate service, 26 00:01:42,520 --> 00:01:47,860 but actually isn't a legitimate service. Besides lava lamps, some of Cloudflare's offices 27 00:01:47,860 --> 00:01:51,620 use swinging pendulums or rainbow mobiles 28 00:01:51,620 --> 00:01:56,060 that get blown around by the air conditioning. Even if someone were to walk in front of these installations 29 00:01:56,060 --> 00:01:59,260 and the camera captures their photo, that's actually completely fine, 30 00:01:59,260 --> 00:02:02,300 as that just adds a different kind of randomness to the image. 31 00:02:02,300 --> 00:02:07,700 Cloudflare even has an installation in Singapore where the natural decay of a chunk of uranium 32 00:02:07,700 --> 00:02:13,260 is the randomness source. But why all this rigmarole? It turns out computers are much worse 33 00:02:13,260 --> 00:02:16,260 than Mother Nature at generating true randomness. 34 00:02:16,260 --> 00:02:20,380 While there are lots of easily accessible random number generators out there, 35 00:02:20,380 --> 00:02:24,300 many of them are pseudo random rather than truly random. 36 00:02:24,300 --> 00:02:27,640 But what's the difference? Well, pseudo random number generators 37 00:02:27,640 --> 00:02:33,420 produce numbers by using an algorithm, meaning that they're predictable if you know the seed, 38 00:02:33,420 --> 00:02:37,300 as the same seed will produce the same output every time. 39 00:02:37,300 --> 00:02:42,220 Unless that seed is truly random, there's no actual true randomness in the process, 40 00:02:42,220 --> 00:02:46,060 meaning that you could guess a cryptographic key if you know the seed. 41 00:02:46,060 --> 00:02:51,740 And on many pseudo random number generators, that may not be that hard to do 42 00:02:51,740 --> 00:02:57,540 if the seed is something fairly easy to guess, like the date or the time as are commonly used. 43 00:02:57,540 --> 00:03:03,340 And this might be fine if you're just trying to decide on a random number for something like a D20 role 44 00:03:03,340 --> 00:03:06,500 in your D&D game. But for trying to keep internet traffic secure, 45 00:03:06,500 --> 00:03:11,100 a truly random hard to guess seed from a natural entropy source is essential. 46 00:03:11,100 --> 00:03:14,700 But if you're in need of a random number generator in your own home for whatever reason, 47 00:03:14,700 --> 00:03:18,740 we recommend lava lamps over radioactive materials 48 00:03:18,740 --> 00:03:22,020 in the long term, they're less bad for you. Thanks for watching guys. 49 00:03:22,020 --> 00:03:25,840 If you liked this video, check out our other video on a Cloudflare mishap 50 00:03:25,840 --> 00:03:29,020 that took a good chunk of internet offline. 51 00:03:29,020 --> 00:03:30,060 Those guys.