1. NIST, “NIST Brief Comments on Recent Cryptanalytic Attacks on Secure Hashing Functions and Continued Security Provided by SHA-1”, 25th August 2004, http://csrc.nist.gov/groups/ST/toolkit/documents/shs/hash_s tandards_comments.pdf
2. Federal Information Processing Standards Publication 180-3, “SECURE HASH STANDARD”, October 2008,
3. http://csrc.nist.gov/publications/fips/fips180-3/fips180-3_final.pdf
4. OpenSSL Source Code, http://www.openssl.org/source
5. N. Ferguson et al, “The Skein Hash Function Family”, Version 1.3, 1st October 2010,