Message Digest 5
Message Digest 5 (MD5) is the fifth in a series of cryptographic hash functions designed by Ronald Rivest. Created in 1991, MD5 takes a block of data of variable length and calculates a 128-bit hash value. This hash value to be used to provide a digital signature or to provide an error check code. Because of vulnerabilities that have been found in the algorithm it is more commonly used for the latter than the former.
As early as 1993, however, MD5 was shown to be prone to collisions which could be identified using a birthday attack. A collision is a variant data structure that has the same hashing value and can be substituted without detection. It is now possible to identify such collisions in less than one minute using a conventional notebook computer. This renders MD5 less attractive as a vehicle for digital signatures and it has since been largely replaced with such algorithms as SHA-1 or RIPEMD-160.
It remains widely used, however, as an error-check code for stored files.
|<mp3>http://podcast.hill-vt.com/podsnacks/2007q4/md5.mp3%7Cdownload</mp3> | Message Digest 5 (MD5)|