1 00:00:08,136 --> 00:00:12,866 We use it everyday and we certainly rely on it. 2 00:00:13,016 --> 00:00:17,876 Although cryptography began thousands of years ago, mathematical analysis 3 00:00:17,876 --> 00:00:22,626 of encrypted communications has effectively altered the course of history. 4 00:00:26,126 --> 00:00:32,466 The most important Japanese code in World War 2 was used by the Japanese navy. 5 00:00:33,466 --> 00:00:42,596 And the breaking of that code turned out to be the most significant source 6 00:00:42,756 --> 00:00:48,766 of intelligence information available to the allied forces. 7 00:00:48,766 --> 00:00:55,656 Japanese navy made several fundamental blunders in the development of the code. 8 00:00:55,656 --> 00:01:02,586 Instead of having a 100,000 possible code book entries the maximum numbers you can have was 9 00:01:02,586 --> 00:01:08,946 33,334 cause that's the number of multiples of three with five digits. 10 00:01:09,576 --> 00:01:15,406 That turned out to be an absolutely critical blunder because it enabled the codes 11 00:01:16,026 --> 00:01:25,116 to be broken steadily in time for the famous Battle of Midway in the middle of 1942, 12 00:01:25,116 --> 00:01:30,386 so the American navy knew exactly what the Japanese battle plan would be. 13 00:01:30,386 --> 00:01:30,453 [ airplanes, gun fire ] 14 00:01:30,453 --> 00:01:32,236 Suddenly, the trap is sprung. 15 00:01:34,506 --> 00:01:37,226 The invasion forces were hit, and hit, and hit again. 16 00:01:40,226 --> 00:01:46,726 In World War 2 the Germans needed a mechanism to automate cryptography. 17 00:01:46,726 --> 00:01:50,066 The invention of the Enigma, an electromechanical rotor machine, 18 00:01:50,596 --> 00:01:55,696 made it easy for operators to just type in a daily key to encrypt their message, 19 00:01:56,176 --> 00:01:57,916 which the other end could then de-crypt. 20 00:01:59,056 --> 00:02:03,726 The clever mathematicians at Bletchley Park in the UK, including Alan Turing, 21 00:02:04,036 --> 00:02:07,066 the father of computers, managed to break the Enigma. 22 00:02:10,736 --> 00:02:14,996 I'm head of the Crypomathematics Research Discipline in the Defence Science 23 00:02:15,106 --> 00:02:23,626 and Technology Organisation DSTO and our role is to support defence research into cryptography 24 00:02:24,016 --> 00:02:30,506 and crypt analysis to support defence future security and Australian national security. 25 00:02:30,566 --> 00:02:38,166 Defence to do its role needs to ensure that they can communicate effectively [yeah cheers thanks] 26 00:02:39,276 --> 00:02:43,816 and securely [comms on maintaining in the vicinity, over] 27 00:02:43,916 --> 00:02:48,396 troops overseas on dangerous operations need to be able to communicate to their base 28 00:02:48,396 --> 00:02:52,606 [ on mission] And so all of those links are need to be real time 29 00:02:52,816 --> 00:02:58,256 and secure otherwise peoples lives are jeopardised [Victor Tango 4 2 5 2] What came 30 00:02:58,466 --> 00:03:07,266 out after World War 2 which revolutionised cryptography was a system called RSA, 31 00:03:07,466 --> 00:03:10,856 the initials of the three people who developed it. 32 00:03:11,316 --> 00:03:15,376 Traditionally you had symmetrical encryption, you had to have the same key, 33 00:03:16,126 --> 00:03:19,906 the breakthrough really was in coming up with this idea of an asymmetric algorithm 34 00:03:19,906 --> 00:03:23,636 where you needed two different keys one of which you could make public the other one so long 35 00:03:23,636 --> 00:03:25,666 as you kept it secret you could be assured 36 00:03:25,776 --> 00:03:28,896 that the communications people were sending you were secure. 37 00:03:30,106 --> 00:03:34,526 It's quite easy to multiply 2 numbers together, it is a much harder problem to look 38 00:03:34,526 --> 00:03:40,736 at a huge number and ask what two numbers were multiplied together to form that number. 39 00:03:40,736 --> 00:03:46,226 So to make the RSA problem as hard as possible you create these two secret prime numbers you 40 00:03:46,226 --> 00:03:50,696 multiply them together, you get a very big composite number which means it can be broken 41 00:03:51,096 --> 00:03:55,446 up as product and you're the only one that knows how to do that. 42 00:03:55,446 --> 00:03:58,856 Pierre de Fermat proved his little theorem in 1640. 43 00:03:59,996 --> 00:04:04,256 It is an important component in proving that RSA cryptography works. 44 00:04:07,836 --> 00:04:13,376 I'm a principal security consultant in the information security group at Westpac. 45 00:04:13,506 --> 00:04:16,796 Cryptography and banking is very important in today's society. 46 00:04:17,026 --> 00:04:23,336 It gives us the ability for us to trust the customer, to manage risk, to reduce fraud. 47 00:04:24,066 --> 00:04:28,236 If you look at a modern credit card you'll see a little gold chip on the card 48 00:04:28,236 --> 00:04:34,426 and on that chip is special circuitry that enables information to be encrypted 49 00:04:34,426 --> 00:04:37,026 and decrypted in a very safe way. 50 00:04:37,716 --> 00:04:42,766 The beauty of modern cryptography is that it is invisible. 51 00:04:43,136 --> 00:04:46,026 An example of that would be using internet banking. 52 00:04:46,336 --> 00:04:50,126 The customer's browser and our internet banking server talk to one another. 53 00:04:50,156 --> 00:04:54,546 All communications between the browser and the server are encrypted. 54 00:04:54,686 --> 00:05:01,406 For certain customers of Westpac that transact in very large amounts of money, 55 00:05:01,696 --> 00:05:06,716 we augment the internet password with an additional layer 56 00:05:06,716 --> 00:05:11,516 of security we use an RSA token device that we give to the customer. 57 00:05:11,686 --> 00:05:15,326 You'll see 6 numbers displayed on the front of that token. 58 00:05:15,596 --> 00:05:18,306 The number is derived from the time of day 59 00:05:18,306 --> 00:05:22,256 and also a secret encryption key that's unique to every token. 60 00:05:22,346 --> 00:05:27,296 Those 6 numbers change every 60 seconds and that number can only be used once by the customer 61 00:05:27,476 --> 00:05:30,806 to log on or authenticate with our server. 62 00:05:30,806 --> 00:05:35,346 Without that mathematics the cryptography would not be possible and without 63 00:05:35,386 --> 00:05:38,166 that cryptography modern banking would not be possible. 64 00:05:42,516 --> 00:05:47,526 Our business is the application of cryptography to solve real world problems 65 00:05:47,606 --> 00:05:50,236 on high speed optical communication systems. 66 00:05:50,696 --> 00:05:55,916 So our customers tend be people who care deeply about the security of their information. 67 00:05:55,916 --> 00:06:02,276 That includes military and defence type organisations, all branches of government, 68 00:06:02,386 --> 00:06:07,006 the financial sector, in the industrial sector, in the mining infrastructure. 69 00:06:07,006 --> 00:06:11,476 And we have to use symmetric rather 70 00:06:11,476 --> 00:06:15,156 than asymmetric encryption algorithms because they're much faster. 71 00:06:15,626 --> 00:06:20,916 We have to transfer securely the encryption key from the sender to the receiver 72 00:06:21,336 --> 00:06:26,656 across the network and to do that we do use a symmetric RSA encryption in our products. 73 00:06:27,376 --> 00:06:33,146 We use AES 256 bit symmetric encryption to encrypt the data keys and we use RSA encryption 74 00:06:33,376 --> 00:06:38,826 with the key size of 2048 bit to securely exchange those data encrypting keys 75 00:06:39,086 --> 00:06:43,776 across the network The challenges aren't going away. 76 00:06:44,146 --> 00:06:48,376 Networks are getting faster, the bad guys are getting cleverer, it's really a constant war 77 00:06:48,376 --> 00:06:52,176 between the code makers and the code breakers so we need the best and brightest minds 78 00:06:52,176 --> 00:06:59,576 to help us with that problem in the future.