- RIPEMD
RIPEMD-160 (RACE Integrity Primitives Evaluation Message Digest) is a 160-bit
message digest algorithm (andcryptographic hash function ) developed inLeuven (Belgium) byHans Dobbertin ,Antoon Bosselaers andBart Preneel at theCOSIC research group at theKatholieke Universiteit Leuven , and first published in 1996. It is an improved version of RIPEMD, which in turn was based upon the design principles used inMD4 , 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 accidental collision, 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, e.g., the
NSA -designed family of algorithms,SHA . On the other hand, RIPEMD-160 appears to be used somewhat less frequently than SHA-1, which may have caused it to be less scrutinised than SHA-1.RIPEMD-160 is not known to be constrained by any patents.
In August 2004, a collision was reported for the original RIPEMD [http://eprint.iacr.org/2004/199.pdf (PDF)] . This does not apply to RIPEMD-160.
RIPEMD-160 hashes
The 160-bit RIPEMD-160 hashes (also termed RIPE "message digests") are typically represented as 40-digit
hexadecimal numbers. The following demonstrates a 43-byteASCII input and the corresponding RIPEMD-160 hash:RIPEMD-160("The quick brown fox jumps over the lazy dog") = 37f332f68db77bd9d7edd4969571ad671cf9dd3b
Even a small change in the message will (with overwhelming probability) result in a completely different hash, e.g. changing d to c:
RIPEMD-160("The quick brown fox jumps over the lazy cog") = 132072df690933835eb8b6ad0b77e7b6f14acad7
The hash of a zero-length string is:
RIPEMD-160("") = 9c1185a5c5e9fc54612808977ee8f548b2258d31
ee also
*
Topics in cryptography External links
* [http://www.infosec.sdu.edu.cn/paper/md4-ripemd-attck.pdf An attack on the original MD4-based RIPEMD]
* [http://www.esat.kuleuven.ac.be/~bosselae/ripemd160.html RIPEMD-160: A Strengthened Version of RIPEMD] (RIPEMD-160 specification and reference implementation)
* [http://www.hashemall.com Hash'em all!] — free online text and file hashing with different algorithms (including RIPEMD)
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