message digest no. 4 (MD4)

Message Digest no. 4 (MD4) is a hash function for encryptingdigital signatures. MD4 was developed by Ronald L. Rivest especially for use on 32-bit computers. The block length is 512 bits and the hash value is 128 bits. MD4 was designed for use with digital signatures, and targets large compressed files encrypted with a public key.

The MD4 algorithm, from which MD5 evolved, is not considered secure. It is described in RFC 1186 from 1990 and was replaced by RFC 1320 from 1992.