RIPEMD

RIPEMD-160 (RACE Integrity Primitives Evaluation Message Digest) is a 160-bit message digest algorithm (andcryptographic hash function) developed in Leuven (Belgium) by Hans Dobbertin, Antoon Bosselaers and Bart Preneel at theCOSIC research group at the Katholieke Universiteit Leuven, and first published in 1996. It is an improved version ofRIPEMD, which in turn was based upon the design principles used in MD4, and is similar in performance to the more popularSHA-1.

There also exist 128, 256 and 320-bit versions of this algorithm, called RIPEMD-128, RIPEMD-256, and RIPEMD-320, respectively. The 128-bit version was intended only as a drop-in replacement for the original RIPEMD, which was also 128-bit, and which had been found to have questionable security. The 256 and 320-bit versions diminish only the chance of accidentalcollision, and don't have higher levels of security as compared to, respectively, RIPEMD-128 and RIPEMD-160.

RIPEMD-160 was designed in the open academic community, in contrast to the NSA-designed SHA-1 and SHA-2 algorithms. On the other hand, RIPEMD-160 appears to be used somewhat less frequently than SHA-1, which may have caused it to be less scrutinized than SHA.