Difference between revisions of "Skein"

From The ECRYPT Hash Function Website
(added Gligoroski's paper)
(http://eprint.iacr.org/2010/355 added)
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A description of the tables is given [http://ehash.iaik.tugraz.at/wiki/Cryptanalysis_Categories#Individual_Hash_Function_Tables here].
 
A description of the tables is given [http://ehash.iaik.tugraz.at/wiki/Cryptanalysis_Categories#Individual_Hash_Function_Tables here].
  
−
Recommended security parameter: '''72''' rounds
+
Recommended security parameter: '''72''' rounds (Skein-512)
  
 
=== Hash function ===
 
=== Hash function ===
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| Type of Analysis || Hash Function Part || Hash Size (n) || Parameters/Variants || Compression Function Calls || Memory Requirements ||  Reference  
 
| Type of Analysis || Hash Function Part || Hash Size (n) || Parameters/Variants || Compression Function Calls || Memory Requirements ||  Reference  
 
|-
 
|-
−
|-  
+
| near-collision || compression function || all || 24 rounds (No. 20-43) || 2<sup>230</sup>  || - || [http://eprint.iacr.org/2010/355.pdf Su,Wu,Wu,Dong]
−
| observations || hash || all || ||  ||  || [http://people.item.ntnu.no/~danilog/Hash/Non-random-behaviour-narrow-pipe-designs-03.pdf Gligoroski]
+
|-
 +
| near-collision || compression function || 256 || 24 rounds (No. 12-35), Skein-256 || 2<sup>60</sup>  || - || [http://eprint.iacr.org/2010/355.pdf Su,Wu,Wu,Dong]
 +
|-
 +
| near-collision || compression function || all || 24 rounds, Skein-1024 || 2<sup>395</sup>  || - || [http://eprint.iacr.org/2010/355.pdf Su,Wu,Wu,Dong]
 +
|-
 +
| observations || hash || all || ||  ||  || [http://people.item.ntnu.no/~danilog/Hash/Non-random-behaviour-narrow-pipe-designs-03.pdf Gligoroski]
 
|-
 
|-
 
|  observations || block cipher || all || - || - || - || [http://eprint.iacr.org/2010/282.pdf McKay,Vora]
 
|  observations || block cipher || all || - || - || - || [http://eprint.iacr.org/2010/282.pdf McKay,Vora]
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|}         
 
|}         
  
 +
 +
<bibtex>
 +
@misc{blakeSuWWD10,
 +
  author = {Bozhan Su and Wenling Wu and Shuang Wu and Le Dong},
 +
  title = {Near-Collisions on the Reduced-Round Compression Functions of Skein and BLAKE},
 +
  howpublished = {Cryptology ePrint Archive, Report 2010/355},
 +
  year = {2010},
 +
  url = {http://eprint.iacr.org/2010/355.pdf},
 +
  abstract = {The SHA-3 competition organized by NIST aims to find a new hash standard as a replacement of SHA-2. Till now, 14 submissions have been selected as the second round candidates, including Skein and BLAKE, both of which have components based on modular addition, rotation and bitwise XOR (ARX). In this paper, we propose improved near-collision attacks on the reduced-round compression functions of Skein and a variant of BLAKE. The attacks are based on linear differentials of the modular additions. The computational complexity of near-collision attacks on a 4-round compression function of BLAKE-32, 4-round and 5-round compression functions of BLAKE-64 are 2^{21}, 2^{16} and 2^{216} respectively, and the attacks on a 24-round compression functions of Skein-256, Skein-512 and Skein-1024 have a complexity of 2^{60}, 2^{230} and 2^{395} respectively.}
 +
}
 +
</bibtex>
  
 
<bibtex>
 
<bibtex>

Revision as of 14:11, 5 July 2010

1 The algorithm


Niels Ferguson, Stefan Lucks, Bruce Schneier, Doug Whiting, Mihir Bellare, Tadayoshi Kohno, Jon Callas, Jesse Walker - The Skein Hash Function Family

,2009
http://www.skein-hash.info/sites/default/files/skein1.2.pdf
Bibtex
Author : Niels Ferguson, Stefan Lucks, Bruce Schneier, Doug Whiting, Mihir Bellare, Tadayoshi Kohno, Jon Callas, Jesse Walker
Title : The Skein Hash Function Family
In : -
Address :
Date : 2009

Niels Ferguson, Stefan Lucks, Bruce Schneier, Doug Whiting, Mihir Bellare, Tadayoshi Kohno, Jon Callas, Jesse Walker - The Skein Hash Function Family

,2008
http://www.skein-hash.info/sites/default/files/skein.pdf
Bibtex
Author : Niels Ferguson, Stefan Lucks, Bruce Schneier, Doug Whiting, Mihir Bellare, Tadayoshi Kohno, Jon Callas, Jesse Walker
Title : The Skein Hash Function Family
In : -
Address :
Date : 2008


2 Cryptanalysis

We distinguish between two cases: results on the complete hash function, and results on underlying building blocks.

A description of the tables is given here.

Recommended security parameter: 72 rounds (Skein-512)

2.1 Hash function

Here we list results on the hash function according to the NIST requirements. The only allowed modification is to change the security parameter.

Type of Analysis Hash Size (n) Parameters Compression Function Calls Memory Requirements Reference

2.2 Building blocks

Here we list results on underlying building blocks, and the hash function modified by other means than the security parameter.

Note that these results assume more direct control or access over some internal variables (aka. free-start, pseudo, compression function, block cipher, or permutation attacks).

Type of Analysis Hash Function Part Hash Size (n) Parameters/Variants Compression Function Calls Memory Requirements Reference
near-collision compression function all 24 rounds (No. 20-43) 2230 - Su,Wu,Wu,Dong
near-collision compression function 256 24 rounds (No. 12-35), Skein-256 260 - Su,Wu,Wu,Dong
near-collision compression function all 24 rounds, Skein-1024 2395 - Su,Wu,Wu,Dong
observations hash all Gligoroski
observations block cipher all - - - McKay,Vora
observations compression function all - - - Kaminsky
key recovery block cipher 256 39 rounds 2254.1 - Khovratovich,Nikolic
key recovery block cipher 512 42 rounds 2507 - Khovratovich,Nikolic
key recovery block cipher 512 32 rounds (Round 1) 2226 (2222) 212 Chen,Jia
key recovery block cipher 512 33 rounds (Round 1) 2352.17 (2355.5) - Chen,Jia
near collision compression function 512 17 rounds (Round 1) 224 - Aumasson,Calik,Meier,Ozen,Phan,Varici
distinguisher block cipher 512 35 rounds (Round 1) 2478 - Aumasson,Calik,Meier,Ozen,Phan,Varici
impossible differential block cipher 512 21 rounds (Round 1) - - Aumasson,Calik,Meier,Ozen,Phan,Varici
key recovery block cipher 512 32 rounds (Round 1) 2312 - Aumasson,Calik,Meier,Ozen,Phan,Varici


Bozhan Su, Wenling Wu, Shuang Wu, Le Dong - Near-Collisions on the Reduced-Round Compression Functions of Skein and BLAKE

,2010
http://eprint.iacr.org/2010/355.pdf
Bibtex
Author : Bozhan Su, Wenling Wu, Shuang Wu, Le Dong
Title : Near-Collisions on the Reduced-Round Compression Functions of Skein and BLAKE
In : -
Address :
Date : 2010

Danilo Gligoroski - Narrow-pipe SHA-3 candidates differ significantly from ideal random functions defined over big domains

,2010
http://people.item.ntnu.no/~danilog/Hash/Non-random-behaviour-narrow-pipe-designs-03.pdf
Bibtex
Author : Danilo Gligoroski
Title : Narrow-pipe SHA-3 candidates differ significantly from ideal random functions defined over big domains
In : -
Address :
Date : 2010

Kerry A. McKay, Poorvi L. Vora - Pseudo-Linear Approximations for ARX Ciphers: With Application to Threefish

,2010
http://eprint.iacr.org/2010/282.pdf
Bibtex
Author : Kerry A. McKay, Poorvi L. Vora
Title : Pseudo-Linear Approximations for ARX Ciphers: With Application to Threefish
In : -
Address :
Date : 2010

Alan Kaminsky - Cube Test Analysis of the Statistical Behavior of CubeHash and Skein

,2010
http://eprint.iacr.org/2010/262.pdf
Bibtex
Author : Alan Kaminsky
Title : Cube Test Analysis of the Statistical Behavior of CubeHash and Skein
In : -
Address :
Date : 2010

Jean-Philippe Aumasson, Cagdas Calik, Willi Meier, Onur Ozen, Raphael C.-W. Phan, Kerem Varici - Improved Cryptanalysis of Skein

,2009
http://eprint.iacr.org/2009/438.pdf
Bibtex
Author : Jean-Philippe Aumasson, Cagdas Calik, Willi Meier, Onur Ozen, Raphael C.-W. Phan, Kerem Varici
Title : Improved Cryptanalysis of Skein
In : -
Address :
Date : 2009

Jiazhe Chen, Keting Jia - Improved Related-key Boomerang Attacks on Round-Reduced Threefish-512

,2009
http://eprint.iacr.org/2009/526.pdf
Bibtex
Author : Jiazhe Chen, Keting Jia
Title : Improved Related-key Boomerang Attacks on Round-Reduced Threefish-512
In : -
Address :
Date : 2009

Dmitry Khovratovich, Ivica Nikolic - Rotational Cryptanalysis of ARX

,2010
http://cryptolux.org/mediawiki/uploads/5/5b/Rotational_Cryptanalysis_of_Skein.pdf
Bibtex
Author : Dmitry Khovratovich, Ivica Nikolic
Title : Rotational Cryptanalysis of ARX
In : -
Address :
Date : 2010

2.3 Archive

Jean-Philippe Aumasson, Willi Meier, Raphael Phan - Improved analyis of Threefish

,2009
http://131002.net/data/talks/threefish_rump.pdf
Bibtex
Author : Jean-Philippe Aumasson, Willi Meier, Raphael Phan
Title : Improved analyis of Threefish
In : -
Address :
Date : 2009
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