The MD5 was designed by Professor Ronald L. Rivest of MIT in 1991. The MD5 message-digest algorithm is the most widely used cryptographic hash function producing a 128-bit (16-byte) hash value, typically expressed in text format as a 32 digit hexadecimal number. It was developed to be used with digital signature applications that require large files to be compressed by a secure method before being encrypted with a secret key, under a public key cryptosystem. MD5 is currently a standard, Internet Engineering Task Force (IETF) Request for Comments (RFC) 1321.