SMASH (hash)
Encyclopedia
SMASH is a cryptographic hash function
which was created by Lars R. Knudsen. SMASH comes in two versions: 256-bit and 512-bit. Each version was supposed to rival SHA-256 and SHA-512, respectfully, however, shortly after the SMASH presentation at FSE 2005, an attack vector against SMASH was discovered which left the hash broken.
and 
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
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Cryptographic hash function
A cryptographic hash function is a deterministic procedure that takes an arbitrary block of data and returns a fixed-size bit string, the hash value, such that an accidental or intentional change to the data will change the hash value...
which was created by Lars R. Knudsen. SMASH comes in two versions: 256-bit and 512-bit. Each version was supposed to rival SHA-256 and SHA-512, respectfully, 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 and 
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
Details
The S-boxes in SMASH are derived versions from the SerpentSerpent (cipher)
Serpent is a symmetric key block cipher which was a finalist in the Advanced Encryption Standard contest, where it came second to Rijndael. Serpent was designed by Ross Anderson, Eli Biham, and Lars Knudsen....
ones.