Difference between revisions of "Skein"

From The ECRYPT Hash Function Website
m (same param for all n's)
(Added Kaminsky and McCay/Vora's papers)
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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  
 
|-
 
|-
−
|-    
+
|-  
 +
|  observations || block cipher || all || - || - || - || [http://eprint.iacr.org/2010/282.pdf McCay,Vora]
 +
|-
 +
|  observations || compression function || all || - || - || - || [http://eprint.iacr.org/2010/262.pdf Kaminsky]
 +
|-
 +
|  key recovery || block cipher || 256 || 39 rounds || 2<sup>254.1</sup> || - || [http://cryptolux.org/mediawiki/uploads/5/5b/Rotational_Cryptanalysis_of_Skein.pdf Khovratovich,Nikolic]
 +
|-
 +
|  key recovery || block cipher || 512 || 42 rounds|| 2<sup>507</sup> || - || [http://cryptolux.org/mediawiki/uploads/5/5b/Rotational_Cryptanalysis_of_Skein.pdf Khovratovich,Nikolic]
 +
|-   
 +
|  key recovery || block cipher || 512 || 32 rounds (Round 1) || 2<sup>226</sup> (2<sup>222</sup>) || 2<sup>12</sup> || [http://eprint.iacr.org/2009/526.pdf Chen,Jia]
 +
|- 
 +
|  key recovery || block cipher || 512 || 33 rounds (Round 1) || 2<sup>352.17</sup> (2<sup>355.5</sup>) || - || [http://eprint.iacr.org/2009/526.pdf Chen,Jia]
 +
|-
 
|  near collision || compression function || 512 || 17 rounds (Round 1) || 2<sup>24</sup> || - || [http://eprint.iacr.org/2009/438.pdf Aumasson,Calik,Meier,Ozen,Phan,Varici]
 
|  near collision || compression function || 512 || 17 rounds (Round 1) || 2<sup>24</sup> || - || [http://eprint.iacr.org/2009/438.pdf Aumasson,Calik,Meier,Ozen,Phan,Varici]
 
|-     
 
|-     
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|  key recovery || block cipher || 512 || 32 rounds (Round 1) || 2<sup>312</sup> || - || [http://eprint.iacr.org/2009/438.pdf Aumasson,Calik,Meier,Ozen,Phan,Varici]
 
|  key recovery || block cipher || 512 || 32 rounds (Round 1) || 2<sup>312</sup> || - || [http://eprint.iacr.org/2009/438.pdf Aumasson,Calik,Meier,Ozen,Phan,Varici]
 
|-     
 
|-     
−
|  key recovery || block cipher || 512 || 32 rounds (Round 1) || 2<sup>226</sup> (2<sup>222</sup>) || 2<sup>12</sup> || [http://eprint.iacr.org/2009/526.pdf Chen,Jia]
 
−
|- 
 
−
|  key recovery || block cipher || 512 || 33 rounds (Round 1) || 2<sup>352.17</sup> (2<sup>355.5</sup>) || - || [http://eprint.iacr.org/2009/526.pdf Chen,Jia]
 
−
|-
 
−
|  key recovery || block cipher || 256 || 39 rounds || 2<sup>254.1</sup> || - || [http://cryptolux.org/mediawiki/uploads/5/5b/Rotational_Cryptanalysis_of_Skein.pdf Khovratovich,Nikolic]
 
−
|-
 
−
|  key recovery || block cipher || 512 || 42 rounds|| 2<sup>507</sup> || - || [http://cryptolux.org/mediawiki/uploads/5/5b/Rotational_Cryptanalysis_of_Skein.pdf Khovratovich,Nikolic]
 
−
|-
 
 
|}         
 
|}         
  
  
 +
<bibtex>
 +
@misc{skeinMV10,
 +
    author = {Kerry A. McKay and Poorvi L. Vora},
 +
    title = {Pseudo-Linear Approximations for ARX Ciphers: With Application to Threefish},
 +
    howpublished = {Cryptology ePrint Archive, Report 2010/282},
 +
    year = {2010},
 +
    url = {http://eprint.iacr.org/2010/282.pdf},
 +
    note = {\url{http://eprint.iacr.org/}},
 +
    abstract = {The operations addition modulo 2^n and exclusive-or have recently been combined to obtain an efficient mechanism for nonlinearity in block cipher design. In this paper, we show that ciphers using this approach may be approximated by pseudo-linear expressions relating groups of contiguous bits of the round key, round input, and round output. The bias of an approximation can be large enough for known plaintext attacks. We demonstrate an application of this concept to a reduced-round version of the Threefish block cipher, a component of the Skein entry in the secure hash function competition.}
 +
}
 +
</bibtex>
  
 +
<bibtex>
 +
@misc{skeinKam10,
 +
    author = {Alan Kaminsky},
 +
    title = {Cube Test Analysis of the Statistical Behavior of CubeHash and Skein},
 +
    howpublished = {Cryptology ePrint Archive, Report 2010/262},
 +
    year = {2010},
 +
    url = {http://eprint.iacr.org/2010/262.pdf},
 +
    note = {\url{http://eprint.iacr.org/}},
 +
    abstract = {This work analyzes the statistical properties of the SHA-3 candidate cryptographic hash algorithms CubeHash and Skein to try to find nonrandom behavior. Cube tests were used to probe each algorithm's internal polynomial structure for a large number of choices of the polynomial input variables. The cube test data were calculated on a 40-core hybrid SMP cluster parallel computer. The cube test data were subjected to three statistical tests: balance, independence, and off-by-one. Although isolated statistical test failures were observed, the balance and off-by-one tests did not find nonrandom behavior overall in either CubeHash or Skein. However, the independence test did find nonrandom behavior overall in both CubeHash and Skein. }
 +
}
 +
</bibtex>
  
 
<bibtex>
 
<bibtex>

Revision as of 13:46, 27 May 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

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
observations block cipher all - - - McCay,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


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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