Rahul Sharma (Editor)

SMASH (hash)

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Designers
  
Lars R. Knudsen

Digest sizes
  
256 or 512 bits

First published
  
2005

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, respectively, however, shortly after the SMASH presentation at FSE 2005, an attack vector against SMASH was discovered which left the hash broken.

Contents

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 θ ∈ G F ( 2 n )

  • h 0 = f ( i v ) ⊕ i v
  • h i = h ( h i − 1 , m i ) = f ( h i 1 ⊕ m i ) ⊕ m i ⊕ θ m i
  • h t + 1 = f ( h t ) ⊕ 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

    Details

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

    References

    SMASH (hash) Wikipedia
    (Text) CC BY-SA