View source for Snefru

{{Short description|Cryptographic hash function}}
{{about|the cryptographic hash function|the Egyptian pharaoh|Sneferu}}

'''Snefru''' is a [[cryptographic hash function]] invented by [[Ralph Merkle]]
in 1990 while working at [[Xerox PARC]].<ref>{{cite journal
| author=Ralph C. Merkle
| journal=[[Journal of Cryptology]]
| volume=3
| issue=1
| pages=43–58
| year=1990
| title=A fast software one-way hash function
| doi=10.1007/BF00203968
| s2cid=33788557
| author-link=Ralph C. Merkle
| doi-access=free
}}</ref>
The function supports 128-bit and 256-bit output. It was named after the [[Ancient Egypt|Egyptian]] [[Pharaoh]] [[Sneferu]], continuing the tradition of the [[Khufu and Khafre#Khufu|Khufu]] and [[Khufu and Khafre#Khafre|Khafre]] [[block cipher]]s.

The original design of Snefru was shown to be insecure by [[Eli Biham]] and [[Adi Shamir]] who were able to use [[differential cryptanalysis]] to find hash collisions. The design was then modified by increasing the number of iterations of the main pass of the algorithm from two to eight. Although differential cryptanalysis can break the revised version with less complexity than [[brute force attack|brute force search]] (a certificational weakness), the attack requires <math>2^{88.5}</math> operations and is thus not currently feasible in practice.<ref>{{cite book
| author=Eli Biham
| title=Fast Software Encryption
| volume=5086
| date=2008-07-19
| location=Fast Software Encryption 2008
| pages=444–461
| doi=10.1007/978-3-540-71039-4_28
| series=Lecture Notes in Computer Science
| isbn=978-3-540-71038-7
| chapter=New Techniques for Cryptanalysis of Hash Functions and Improved Attacks on Snefru
| author-link=Eli Biham
}}</ref>

==References==
{{reflist}}

==External links==
* {{website|https://ehash.iaik.tugraz.at/wiki/Snefru-n|Snefru-n}} on Ecrypt
* {{SourceForge|rhash|RHash}}, an [[open source]] command-line tool, which can calculate and verify Snefru-128 and Snefru-256

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[[Category:Broken hash functions]]


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