සල්ලි ගරමු - Release 01

[SIZE=4]MD5 Stands for Message Digest 5. It is specified in RFC 1321 and was first[/SIZE] [SIZE=4]published in 1991 by Ronald Rivest. It is represented by a 32-digit long hexadecimal[/SIZE] [SIZE=4]number. It was commonly used along with the rest of the message digests up until 1996[/SIZE] [SIZE=4]that revealed vulnerability that drew people to use other algorithms such as SHA-1,[/SIZE] [SIZE=4]which will be explained a little later. Though the original vulnerability wasn’t major it[/SIZE] [SIZE=4]still deterred people from using it and in 2004 a major vulnerability was discovered and [/SIZE][SIZE=4]led to many abandoning it.[/SIZE] [SIZE=4]MD5 is described below:[/SIZE]

[SIZE=4]1.The message's length is extended to 448-bits. Even when the message is equal to 448,[/SIZE]
[SIZE=4]this step is still performed.[/SIZE]

[SIZE=4]2. The 64-bit message before padding is appended to the end result of the previous step.[/SIZE]

[SIZE=4]3. A buffer is used to create a message digest. The buffer consists of four-words.[/SIZE]

[SIZE=4]4.Three functions are defined with three 32-bit words and spits out one 32-bit word.[/SIZE]

[SIZE=4]5. The message digest produces the output.[/SIZE]
[SIZE=4]According to RFC 1321 the differences are as following:[/SIZE]
[SIZE=4]• A fourth round has been added.[/SIZE]
[SIZE=4]• 2. Each step now has a unique additive constant.[/SIZE]
[SIZE=4]• 4. Each step now adds in the result of the previous step. This[/SIZE]
[SIZE=4]promotes a faster "avalanche effect".[/SIZE]

[SIZE=4]5. The order in which input words are accessed in rounds 2 and[/SIZE] [SIZE=4]3 is changed, to make these patterns less like each other.[/SIZE]

[SIZE=4]• The shift amounts in each round have been approximately[/SIZE]
[SIZE=4]optimized, to yield a faster "avalanche effect." The shifts in[/SIZE]
[SIZE=4]different rounds are distinct.[/SIZE]