From The ECRYPT Hash Function Website
Revision as of 10:51, 12 October 2006 by Nobbi (talk | contribs) (Claimed Security Margins)

1 General Description

SHA-1 is an iterated hash function.

1.1 Compression Function

The compression function takes as input a 512-bit message block and a 160-bit chaining variable, and produces a 160-bit chaining value. The compression function is described as follows:

1.1.1 Message Expansion

The message expansion is defined as follows:


1.1.2 State Update Transformation


1.2 Padding Method

1.3 Constantsand Initial Value

1.3.1 Constants


1.3.2 Initial Value


2 Claimed/Expected Security Margins

3 Security Anaylsis

  • Best know attack: math by Wang
  • Best known collision example: 64-step collision by De Canniere and Rechberger

something like: best know attack to date: kind of attack, which variant has been looked at (e.g. round-reduced), complexity, and reference to paper and abstract.

may be make here a new page with the other cryptanalysis results.