04-04-2013, 04:20 PM
SHA-2 Algorithms
SHA-2 Algorithms.ppt (Size: 99 KB / Downloads: 207)
SHA History
1993
The hash function SHA-0 was issued as a federal standard by NIST
1995
SHA-1 published as the successor to SHA-0
2002
SHA-2 variants
SHA-256, SHA-384, and SHA-512 published
2004
SHA-224 published
SHA-256
Message is processed in 512-bit blocks sequentially, just like SHA-1
Message digest is 256 bits instead of SHA-1’s 160-bits
64 rounds instead of 80 rounds of compression
Algorithm structure same as SHA-1
Step 1: Padding bits
Step 2: Appending length as 64 bit unsigned
Step 3: Buffer initiation
Step 4: Processing of message
Step 5: Output