MD4
The MD4 (Message-Digest Algorithm 4) is a cryptographic hash function developed by Ronald Rivest in 1990. The digest length is 128 bits. The algorithm has influenced later designs, such as the MD5, SHA-1 and RIPEMD algorithms.[1]
The security of MD4 has been severely compromised. The first full collision attack against MD4 was published in 1995 and several newer attacks have been published since then. As of 2007, an attack can generate collisions in less than 2 MD4 hash operations. A theoretical preimage attack also exists.[1]
WARNING:
MD4 should not be used anylonger for cryptographic operations!