SMASH (hash)

SMASH
General
Designers	Lars R. Knudsen
First published	2005
Detail
Digest sizes	256 or 512 bits
Best public cryptanalysis
Collision,^[1] Second Preimage^[2]

SMASH is a cryptographic hash function which was created by Lars R. Knudsen.^[3] SMASH comes in two versions: 256-bit and 512-bit. Each version was supposed to rival SHA-256 and SHA-512, respectively, however, shortly after the SMASH presentation at FSE 2005, an attack vector against SMASH was discovered which left the hash broken.

Specifications

The message length was limited to less than 2¹²⁸ for SMASH-256 and 2²⁵⁶ for SMASH-512.

Definition

Input: 256/512-bit message blocks $m_{1},m_{2},...,m_{t}$ and $\theta \in GF(2^{n})$

$h_{0}=f(iv)\oplus iv$
$h_{i}=h(h_{i-1},m_{i})=f(h_{i_{1}}\oplus m_{i})\oplus m_{i}\oplus \theta m_{i}$
$h_{t+1}=f(h_{t})\oplus h_{t}$

The function f is a complex compression function consisting of H-Rounds and L-Rounds using S-boxes, linear diffusion and variable rotations, details can be found here ^[3]

Details

The S-boxes in SMASH are derived versions from the Serpent ones.

References

↑ Pramstaller, Norbert; Rechberger, Christian; Rijmen, Vincent (2006). "Breaking a New Hash Function Design Strategy Called SMASH". Lecture Notes in Computer Science. 3897: 233–244. doi:10.1007/11693383_16.
↑ Lamberger, Mario; Pramstaller, Norbert; Rechberger, Christian; Rijmen, Vincent (2006). "Second Preimages for SMASH". Lecture Notes in Computer Science. 4377: 101–111. doi:10.1007/11967668_7.
1 2 Knudsen, Lars R.: SMASH - A Cryptographic Hash Function, Accessed 23 November 2009

Cryptographic hash functions & message authentication codes

List Comparison Known attacks

Common functions	MD5 SHA-1 SHA-2 SHA-3 BLAKE2 SipHash

SHA-3 finalists	BLAKE Grøstl JH Skein Keccak (winner)

Other functions	ECOH FSB GOST HAS-160 HAVAL Kupyna LM hash MD2 MD4 MD5 MD6 MDC-2 N-Hash RIPEMD RadioGatún SWIFFT Snefru Streebog Tiger VSH WHIRLPOOL

Key derivation functions	bcrypt crypt PBKDF2 scrypt Argon2 Lyra2

MAC functions	DAA CBC-MAC HMAC OMAC/CMAC PMAC VMAC UMAC Poly1305

Authenticated encryption modes	CCM 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

Standardization	CRYPTREC NESSIE NIST hash function competition

Utilization	Hash-based cryptography Key stretching Merkle tree Message authentication Proof of work Salt

Cryptography

History of cryptography Cryptanalysis Outline of cryptography

Symmetric-key algorithm Block cipher Stream cipher Public-key cryptography Cryptographic hash function Message authentication code Random numbers Steganography

Category Portal WikiProject

This article is issued from Wikipedia - version of the 8/23/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.