MD5

MD5 (Message Digest Algorithm 5) is a cryptographic hash function, which hashes a string of arbitrary length into a 128 bit hash value. MD5 is one of a series of message digest functions designed by Professor [Ronald Rivest]? of MIT. It is an extension of it spredecessor, MD4, in response to some analytic work indicating that MD4 was likely to be insecure. MD4 has since been shown to be cryptographically insecure. MD5 has been widely used, and until recently was thought to be cryptographically secure. Recent work in Germany has uncovered weaknesses which make further use of MD5 questionable; as of this writing it has not been 'broken' as has MD4. SHA-1 (the revised algorithm), or any of several others, would appear to be a better choice. SHA-1 has also been seriously examined, but so far no results have been reported which suggest it is (or is likely to be found) cryptographically insecure.