Date Added: Mar 2012
Hash functions are tools used in integrity of messages, digital signatures and digital time stamping. Message digest algorithms started with public key cryptography for authentication. Digest algorithms compute some hash functions, which are message digest values based on a simple set of primitive operations of 32-bit words. Among the digest algorithms MD4 and MD5 are most popular. Both these algorithms perform a set of bitwise logical operations. They generate 128-bit digest values from a given message. Time complexity of MD5 is more than MD4 and hence somewhat slower to execute. The message digest algorithms MD4, MD5 have been discussed in detail. A new method has been introduced for obtaining collisions for reduced number of rounds of MD4 and MD5 algorithms.