1 00:00:08,480 --> 00:00:11,390 Let us begin with the last lesson in cryptography. 2 00:00:13,180 --> 00:00:19,600 In this video, we will discuss for discussing the importance of fishing and types of fishing that is 3 00:00:19,620 --> 00:00:21,130 amplified and S.A.G.. 4 00:00:22,800 --> 00:00:29,040 A cryptographic has function is a hash function, which makes an input like a message and returns a 5 00:00:29,040 --> 00:00:36,750 fixed string of bytes, the string is called hash value message digest, digital fingerprint or checksum. 6 00:00:37,880 --> 00:00:43,880 A hash function is a mathematical function that converts a numerical input value into another complex 7 00:00:43,880 --> 00:00:50,850 numerical value, the input to hash function is of arbitrarily end, but output is always fixed and 8 00:00:51,590 --> 00:00:54,860 an ideal hash function is a one way function. 9 00:00:55,700 --> 00:00:58,580 For every input, there is one unique output. 10 00:00:59,460 --> 00:01:02,160 Two different inputs cannot result in the same output. 11 00:01:03,360 --> 00:01:09,060 The ideal hash function as three main properties, it is extremely easy to calculate. 12 00:01:09,780 --> 00:01:12,060 It is extremely, computationally difficult. 13 00:01:12,840 --> 00:01:18,090 It is extremely unlikely that two slightly different messages will have the same hash value. 14 00:01:19,500 --> 00:01:21,850 A real many to one function. 15 00:01:22,680 --> 00:01:26,620 There is a possibility that more than one input can result in the same output. 16 00:01:27,780 --> 00:01:33,480 How would a hash function is analyzed by checking the probability of more than one inputs having the 17 00:01:33,480 --> 00:01:37,740 same output, the lower the probability, the better is the hash function. 18 00:01:38,220 --> 00:01:44,530 Now let us discuss hashing function with simple Real-Life example Alice. 19 00:01:44,560 --> 00:01:48,690 But this is a tough math problem to Bob and claims he has solved it. 20 00:01:49,530 --> 00:01:54,990 Bob would like to try it himself, but would yet like to be sure that Alice is not bluffing. 21 00:01:55,680 --> 00:02:03,270 Therefore, Alice read the resolution computed and hashes it and tells Bob the hash value while keeping 22 00:02:03,270 --> 00:02:04,180 the origin secret. 23 00:02:04,530 --> 00:02:10,860 Then when Bob comes up with the solution himself after a few days, he can verify Alice had a solution 24 00:02:10,860 --> 00:02:16,050 earlier by calculating the hash and check that it matches the hash value given to him by Alice. 25 00:02:16,710 --> 00:02:18,500 This is a real live example of hashing. 26 00:02:19,110 --> 00:02:24,000 Now we will go back to the diagram shown on your screen here. 27 00:02:24,000 --> 00:02:30,240 An image of cat is put into hashing function, which is a one way function, and we got a petri dish 28 00:02:30,240 --> 00:02:34,790 which has value, which we just can't understand in the message. 29 00:02:35,670 --> 00:02:37,110 I love cybersecurity. 30 00:02:37,440 --> 00:02:42,500 You can see that the input and output are not the same thing. 31 00:02:42,630 --> 00:02:47,700 You can have any input, but output will be of the fixed line in another message. 32 00:02:47,730 --> 00:02:48,920 Welcome to the cyber world. 33 00:02:49,410 --> 00:02:52,440 The output value is just we can't understand anything. 34 00:02:52,740 --> 00:02:56,440 Therefore we can claim that hash function is secure. 35 00:02:57,060 --> 00:02:59,700 Let us discuss types of hashing algorithms. 36 00:03:00,090 --> 00:03:02,710 We will discuss, amplify and S.A.G.. 37 00:03:04,140 --> 00:03:10,770 And if I was most popular and widely used, has functioned for quite some years, the message that I 38 00:03:10,770 --> 00:03:19,140 just family comprises of has functions like Emily to Emily for Emily and MDX, it was adopted as Internet 39 00:03:19,140 --> 00:03:21,210 standard RFQ one, three, two, one. 40 00:03:22,050 --> 00:03:24,030 It is a 128 bit function. 41 00:03:25,140 --> 00:03:31,140 MTV Digest have been widely used in the software world to provide assurance about the integrity of the 42 00:03:31,140 --> 00:03:31,890 transfer file. 43 00:03:32,340 --> 00:03:39,330 For example, file servers often provide a computer and check some other files so that the user can 44 00:03:39,330 --> 00:03:41,660 compare to take some of the downloaded file with. 45 00:03:42,710 --> 00:03:49,040 In 2004, coalitions were formed, namely faith and analytical attack was reported to be successful 46 00:03:49,040 --> 00:03:55,570 only in another by using computer Kluster, the coalition attack resulted in compromise in the faith 47 00:03:55,760 --> 00:03:59,030 and hence it is no longer recommended for use. 48 00:04:00,170 --> 00:04:02,330 Next is the Securus function. 49 00:04:02,570 --> 00:04:12,080 It is the family of such a competitor for S.A.G. algorithm's is such a zero Issachar one as a two and 50 00:04:12,240 --> 00:04:15,140 such a three, both on the same family. 51 00:04:15,440 --> 00:04:17,660 They're actually structurally different. 52 00:04:18,930 --> 00:04:26,700 The original version is a set of zero one 60, which has function was published by the National Institute 53 00:04:26,700 --> 00:04:34,700 of Standards and Technology NIST in 1993, which are few weaknesses and did not become very popular. 54 00:04:35,490 --> 00:04:41,580 Later in 1995, a statue of one was designed to curb alleged weaknesses of a zero. 55 00:04:42,900 --> 00:04:46,760 Issachar One is the most widely used of the existing S.A.G. functions. 56 00:04:47,670 --> 00:04:53,340 It is employed in several widely used applications and protocols, including Secure Sockets Layer that 57 00:04:53,340 --> 00:04:56,940 is the SSL security in 2005. 58 00:04:57,090 --> 00:05:02,820 And Metallo was found for uncovering collisions for a situation with impractically making a long term 59 00:05:02,820 --> 00:05:11,880 employability of such a wonderful Isatou family has for further S.A.G. variants like S.A.G. 224, S.A.G. 60 00:05:11,900 --> 00:05:20,990 256 and exegete 384 and Acidify one two, depending upon the number of words in virtually no successful 61 00:05:21,000 --> 00:05:27,630 attacks have been yet reported on S.A.G. to function, though as the data the strong has function, 62 00:05:28,080 --> 00:05:33,000 though significantly different, its basic design is still that follows a situation. 63 00:05:33,660 --> 00:05:39,930 Hence, NIST called for a new competitive hash function in October 2012. 64 00:05:40,650 --> 00:05:48,300 S.P. choose the algorithm as a new set of three standard GTECH offers many benefits such as efficient 65 00:05:48,300 --> 00:05:54,570 performance and good resistance foredeck, therefore such it is stronger than endevour. 66 00:05:55,080 --> 00:05:59,790 Now let us discuss applications of fashion with some real life examples. 67 00:06:00,240 --> 00:06:01,800 The first is password storage. 68 00:06:02,690 --> 00:06:09,200 Instead of suing passwords and clear, mostly all processes store the hash value of passwords in the 69 00:06:09,200 --> 00:06:09,500 file. 70 00:06:10,580 --> 00:06:16,970 The password file consists of a table of papers which are in the form user comma hashed password. 71 00:06:17,950 --> 00:06:22,810 An intruder can only see the ashes of passwords, even if he says the password. 72 00:06:23,530 --> 00:06:29,020 He can neither log on using the hash, nor can it derive the passwords from the hash value since the 73 00:06:29,020 --> 00:06:29,770 hash function. 74 00:06:29,810 --> 00:06:32,380 But this is the property of previous resistance. 75 00:06:33,400 --> 00:06:35,350 Next is Data Integrity Check. 76 00:06:36,380 --> 00:06:42,460 Let's consider an example like I'm going to download, let's say, a pirated version of Windows 10 from 77 00:06:42,460 --> 00:06:43,200 a friend of mine. 78 00:06:43,720 --> 00:06:48,940 But I know and my friend is a crook and he might have tampered with the ISO file. 79 00:06:49,180 --> 00:06:56,020 So I take the has given in the Microsoft website and compare it with the file he is giving these prominent 80 00:06:56,020 --> 00:06:57,700 applications of hashing algorithm.