Difference between revisions of "SHA-1"

From The ECRYPT Hash Function Website
(State Update Transformation)
(State Update Transformation)
Line 9: Line 9:
 
==== State Update Transformation ====
 
==== State Update Transformation ====
 
<amsmath>
 
<amsmath>
     A_{i+1} = A_i \lll 5 + W_i + f(B_i,C_i,D_i) + K_i
+
\begin{aligned}
 +
     A_{i+1} &= A_i \lll 5 + W_i + f(B_i,C_i,D_i) + K_i\\
 +
    B_{i+1} &= A_i\\
 +
\end{aligned}
 
</amsmath>
 
</amsmath>
 
<math>
 
    B_{i+1} = A_i
 
</math>
 
  
 
<math>
 
<math>

Revision as of 13:58, 11 October 2006

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

1.1.2 State Update Transformation

WikiTeX: latex reported a failure, namely:

/data/www/ehash/html/extensions/wikitex/wikitex.sh: line 59: latex: command not found

<math>

   C_{i+1} = B_i >> 2

</math>

<math>

   D_{i+1} = C_i

</math>

<math>

   E_{i+1} = D_i

</math>

1.2 Padding Method

1.3 Initial Value and Constants

WikiTeX: latex reported a failure, namely:

/data/www/ehash/html/extensions/wikitex/wikitex.sh: line 59: latex: command not found

2 Claimed Security Margins

3 Security Anaylsis

  • Best know attack: <math>2^{63}</math> by Wang et.al.
  • 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.