2 The algorithm
2.1 Append Padding Bits
2.2 Append Length
2.3 Initialize MD Buffer
2.4 Process Message in 16-Word Blocks
3 Cryptanalysis of MD5
Ii is almost impossible to design a perfect crypto-system. People nd
new cryptographic algorithms everyday. However, many of the
aws found in
crypto systems don`t make them any less secure or trustworthy since the precon-
ditions required to generate
aws are still computationally expensive in real life.
Researchers have been active to nd possible collisions in MD5. Some has
shown that it could be possible under certain conditions. First few ndings were
not critical for MD5 to be used in real applications because the specic envi-
ronment needed was hard to achieve. However, since MD5 was shown not to be
collision resistant, its uses for the applications began to diminish. Researchers
started to recommend other algorithms such as SHA-1.
These struggles make developments in cryptographic communities and help
new algorithms be resistant to known possible
aws. Although MD5 is now
considered cryptographically broken, this ght between new design and nding
aws in it will continue unless a perfect crypto-system is developed.
Performance analysis of md5, 1995, http://www.isi.edu/touch/pubs/sigcomm95.html.
Md5, 2012, http://en.wikipedia.org/wiki/MD5.
Schneiner Bruce, Opinion: cryptanalysis of md5 and sha: Time for a new
standard, Computerworld (2004).
Ronald Rivest, The md5 message digest algorithm, Internet Network Work-
ing Group RFC 1321 (1992).
Xianyan Wang, Dengguo Feng, Xuejia Lai, and Hongbo Yu, Collisions for
hash functions md4, md5, haval-128 and ripemd, Crypto'04 (2004).