RIPEMD

The 256- and 320-bit versions of RIPEMD provide the same level of security as RIPEMD-128 and RIPEMD-160, respectively; they are designed for applications where the security level is sufficient but longer hash result is necessary.

[citation needed] The original RIPEMD function was designed in the framework of the EU project RIPE (RACE Integrity Primitives Evaluation) in 1992.

In 1996, in response to security weaknesses found in the original RIPEMD,[3] Hans Dobbertin, Antoon Bosselaers and Bart Preneel at the COSIC research group at the Katholieke Universiteit Leuven in Leuven, Belgium published four strengthened variants: RIPEMD-128, RIPEMD-160, RIPEMD-256, and RIPEMD-320.

[8] In December 2023, an improved collision attack was found based on the technique from the previous best collision attack, this improved collision attack could reach 40 rounds out of 80 round with a theoretical time complexity of 249.9.

[9] The 160-bit RIPEMD-160 hashes (also termed RIPE message digests) are typically represented as 40-digit hexadecimal numbers.