Snefru

Cryptographic hash function

Snefru is a cryptographic hash function invented by Ralph Merkle in 1990 while working at Xerox PARC.^[1] The function supports 128-bit and 256-bit output. It was named after the Egyptian Pharaoh Sneferu, continuing the tradition of the Khufu and Khafre block ciphers.

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 search (a certificational weakness), the attack requires $2^{88.5}$ operations and is thus not currently feasible in practice.^[2]

References

^ Ralph C. Merkle (1990). "A fast software one-way hash function". Journal of Cryptology. 3 (1): 43–58. doi:10.1007/BF00203968. S2CID 33788557.
^ Eli Biham (2008-07-19). "New Techniques for Cryptanalysis of Hash Functions and Improved Attacks on Snefru". Fast Software Encryption. Lecture Notes in Computer Science. Vol. 5086. Fast Software Encryption 2008. pp. 444–461. doi:10.1007/978-3-540-71039-4_28. ISBN 978-3-540-71038-7.{{cite book}}: CS1 maint: location (link) CS1 maint: location missing publisher (link)

External links

Snefru-n on Ecrypt
RHash on SourceForge, an open source command-line tool, which can calculate and verify Snefru-128 and Snefru-256

v t e Cryptographic hash functions and message authentication codes
List Comparison Known attacks
Common functions	MD5 (compromised) SHA-1 (compromised) SHA-2 SHA-3 BLAKE2
SHA-3 finalists	BLAKE Grøstl JH Skein Keccak (winner)
Other functions	BLAKE3 CubeHash ECOH FSB Fugue GOST HAS-160 HAVAL Kupyna LSH Lane MASH-1 MASH-2 MD2 MD4 MD6 MDC-2 N-hash RIPEMD RadioGatún SIMD SM3 SWIFFT Shabal Snefru Streebog Tiger VSH Whirlpool
Password hashing/ key stretching functions	Argon2 Balloon bcrypt Catena crypt LM hash Lyra2 Makwa PBKDF2 scrypt yescrypt
General purpose key derivation functions	HKDF KDF1/KDF2
MAC functions	CBC-MAC DAA GMAC HMAC NMAC OMAC/CMAC PMAC Poly1305 SipHash UMAC VMAC
Authenticated encryption modes	CCM ChaCha20-Poly1305 CWC EAX GCM IAPM OCB
Attacks	Collision attack Preimage attack Birthday attack Brute-force attack Rainbow table Side-channel attack Length extension attack
Design	Avalanche effect Hash collision Merkle–Damgård construction Sponge function HAIFA construction
Standardization	CAESAR Competition CRYPTREC NESSIE NIST hash function competition Password Hashing Competition
Utilization	Hash-based cryptography Merkle tree Message authentication Proof of work Salt Pepper

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Mathematics	Cryptographic hash function Block cipher Stream cipher Symmetric-key algorithm Authenticated encryption Public-key cryptography Quantum key distribution Quantum cryptography Post-quantum cryptography Message authentication code Random numbers Steganography
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