RIPEMD-128 (128 bit) is (RACE Integrity Primitives Evaluation Message Digest). RIPEMD-128 is part of message digest family (cryptographic hash functions) developed in Leuven, Belgium, by Hans Dobbertin, Antoon Bosselaers and Bart Preneel at the COSIC research group at the Katholieke Universiteit Leuven, and first published in 1996. RIPEMD was based upon the design principles used in MD4, and is similar in performance to the more popular SHA-1.

The 128-bit RIPEMD-128 hashes (also termed RIPE message digests) are typically represented as 32-digit hexadecimal numbers.