Difference between revisions of "Skein"

From The ECRYPT Hash Function Website
m (references updated)
(Added results of four recent cryptanalysis papers)
 
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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 (Skein-512)
+
Recommended security parameter: '''72''' rounds (Skein-256 and Skein-512)
  
  
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| Type of Analysis || Hash Size (n) || Parameters || Compression Function Calls || Memory Requirements ||  Reference  
 
| Type of Analysis || Hash Size (n) || Parameters || Compression Function Calls || Memory Requirements ||  Reference  
 
|-                     
 
|-                     
−
| || || || || ||
+
| collision || 256 || 2 rounds || 2<sup>85</sup>    || - || [http://eprint.iacr.org/2012/141.pdf Khovratovich]
 +
|-
 +
| collision || 256 || 12 rounds || 2<sup>126.5</sup>  || - || [http://eprint.iacr.org/2012/141.pdf Khovratovich]
 +
|-
 +
| collision || 512 || 5 rounds  || 2<sup>192</sup>    || - || [http://eprint.iacr.org/2012/141.pdf Khovratovich]
 +
|-
 +
| collision || 512 || 14 rounds || 2<sup>254.5</sup>  || - || [http://eprint.iacr.org/2012/141.pdf Khovratovich]
 +
|-                   
 +
| preimage || 512 || 22 rounds || 2<sup>511.0</sup>  || 2<sup>6</sup> || [http://eprint.iacr.org/2011/286.pdf Khovratovich,Rechberger,Savelieva]
 +
|-                   
 +
| preimage || 512 || 72 rounds || 2<sup>511.76</sup>  || - || [http://eprint.iacr.org/2011/286.pdf Khovratovich,Rechberger,Savelieva]
 
|-                     
 
|-                     
 
|}
 
|}
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|- style="background:#efefef;"                   
 
|- style="background:#efefef;"                   
 
| 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  
 +
|-
 +
| preimage || compression function || 512 || 22 rounds || 2<sup>508</sup>  ||  2<sup>6</sup>  || [http://eprint.iacr.org/2011/286.pdf Khovratovich,Rechberger,Savelieva]
 +
|-
 +
| preimage || compression function || 512 || 37 rounds || 2<sup>511.2</sup>  || 2<sup>64</sup> || [http://eprint.iacr.org/2011/286.pdf Khovratovich,Rechberger,Savelieva]
 +
|-
 +
| distinguisher || compression function || 512 || 32 rounds || 2<sup>104.5</sup>  || - || [http://eprint.iacr.org/2012/238.pdf Yu,Chen,Wang]
 +
|-
 +
| distinguisher || compression function || 512 || 36 rounds || 2<sup>454</sup>  || - || [http://eprint.iacr.org/2012/238.pdf Yu,Chen,Wang]
 +
|-
 +
| key recovery || block cipher || 512 || 32 rounds || 2<sup>181</sup>  || - || [http://eprint.iacr.org/2012/238.pdf Yu,Chen,Wang]
 +
|-
 +
| key recovery || block cipher || 512 || 34 rounds || 2<sup>424</sup>  || - || [http://eprint.iacr.org/2012/238.pdf Yu,Chen,Wang]
 +
|-
 +
| near-collision || compression function || 256 || 32 rounds || 2<sup>105</sup>  || - || [http://eprint.iacr.org/2011/148.pdf Yu,Chen,Jia,Wang]
 
|-
 
|-
 
| distinguisher || compression function || all || 57 rounds  (Round 2) || 2<sup>503</sup>  || - || [http://eprint.iacr.org/2010/538.pdf Khovratovich,Nikolić,Rechberger]
 
| distinguisher || compression function || all || 57 rounds  (Round 2) || 2<sup>503</sup>  || - || [http://eprint.iacr.org/2010/538.pdf Khovratovich,Nikolić,Rechberger]
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 +
 +
 +
<bibtex>
 +
@misc{skeinK12,
 +
    author = {Dmitry Khovratovich},
 +
    title = {Bicliques for permutations: collision and preimage attacks in stronger settings},
 +
    howpublished = {Cryptology ePrint Archive, Report 2012/141},
 +
    year = {2012},
 +
    url = {http://eprint.iacr.org/2012/141.pdf},
 +
    abstract = { We extend and improve biclique attacks, which were recently introduced for the cryptanalysis of block ciphers and hash functions. While previous attacks required a primitive to have a key or a message schedule, we show how to mount attacks on the primitives with these parameters fixed, i.e. on permutations. We introduce the concept of sliced bicliques, which is a translation of regular bicliques to the framework with permutations.
 +
 +
The new framework allows to convert preimage attacks into collision attacks and derive the first collision attacks on the reduced SHA-3 finalist Skein in the hash function setting up to 11 rounds. We also demonstrate new preimage attacks on the reduced Skein and the output transformation of the reduced Gr{\o}stl. Finally, the sophisticated technique of message compensation gets a simple explanation with bicliques. }
 +
}
 +
</bibtex>
 +
<bibtex>
 +
@inproceedings{skeinKRS12,
 +
  author = {Dmitry Khovratovich and Christian Rechberger and Alexandra Savelieva},
 +
  title = {Bicliques for Preimages: Attacks on Skein-512 and the SHA-2 family},
 +
  booktitle = {Fast Software Encryption (FSE)},
 +
  year      = {2012},
 +
  publisher = {Springer},
 +
  series    = {LNCS},
 +
  url = {http://eprint.iacr.org/2011/286.pdf},
 +
  abstract = {We present the new concept of biclique as a tool for preimage attacks, which
 +
employs many powerful techniques from differential cryptanalysis of block ciphers and hash
 +
functions.
 +
The new tool has proved to be widely applicable by inspiring many authors to publish new re-
 +
sults of the full versions of AES, KASUMI, IDEA, and Square. In this paper, we demonstrate
 +
how our concept results in the first cryptanalysis of the Skein hash function, and describe an
 +
attack on the SHA-2 hash function with more rounds than before.}
 +
}
 +
</bibtex>
 +
<bibtex>
 +
@misc{skeinY+12,
 +
    author = {Hongbo Yu and Jiazhe Chen and Xiaoyun Wang},
 +
    title = {The Boomerang Attacks on the Round-Reduced Skein-512},
 +
    howpublished = {Cryptology ePrint Archive, Report 2012/238},
 +
    year = {2012},
 +
    url = {http://eprint.iacr.org/2012/238.pdf},
 +
    abstract = {The hash function Skein is one of the five finalists of the NIST SHA-3 competition;it is based on the block cipher Threefish which only uses three primitive operations: modular addition, rotation and bitwise XOR (ARX). This paper studies the boomerang attacks on Skein-512. Boomerang distinguishers on the compression function reduced to 32 and 36 rounds are proposed, with complexities 2^{104.5} and 2^{454} respectively. Examples of the distinguishers on 28-round and 31-round are also given. In addition, the boomerang distinguishers are applicable to the key-recovery attacks on reduced Threefish-512. The complexities for key-recovery attacks reduced to 32-/33-/34-round are about 2^{181}, 2^{305} and 2^{424}. Because Laurent et al. [14] pointed out that the previous boomerang distinguishers for Threefish-512 are in fact not compatible, our attacks are the first valid boomerang attacks for the final round Skein-512.  }
 +
}
 +
</bibtex>
 +
<bibtex>
 +
@misc{skeinY+12,
 +
    author = {Hongbo Yu and Jiazhe Chen and Ketingjia and Xiaoyun Wang},
 +
    title = {Near-Collision Attack on the Step-Reduced Compression Function of Skein-256},
 +
    howpublished = {Cryptology ePrint Archive, Report 2011/148},
 +
    year = {2011},
 +
    url = {http://eprint.iacr.org/2011/148.pdf},
 +
    abstract = {The Hash function Skein is one of the 5 finalists of NIST SHA-3 competition. It is designed based on the threefish block cipher and it only uses three primitive operations: modular addition, rotation and bitwise XOR (ARX). In this paper, we combine two short differential paths to a long differential path using the modular differential technique. And we present the semi-free start near-collision attack up to the 32-step Skein-256 with the Hamming difference 51. The complexity of our attack is about $2^{105}$. }
 +
}
 +
</bibtex>
 
<bibtex>
 
<bibtex>
 
@inproceedings{skeinKNR10,
 
@inproceedings{skeinKNR10,
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}
 
}
 
</bibtex>
 
</bibtex>
−
 
 
<bibtex>
 
<bibtex>
 
@inproceedings{skeinSuWWD10,
 
@inproceedings{skeinSuWWD10,
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}
 
}
 
</bibtex>
 
</bibtex>
−
 
 
<bibtex>
 
<bibtex>
 
@inproceedings{cryptoeprint:2009:526,
 
@inproceedings{cryptoeprint:2009:526,
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}
 
}
 
</bibtex>
 
</bibtex>
−
 
 
<bibtex>
 
<bibtex>
 
@misc{cryptoeprint:2009:526,
 
@misc{cryptoeprint:2009:526,
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}
 
}
 
</bibtex>
 
</bibtex>
−
 
 
<bibtex>
 
<bibtex>
 
@inproceedings{skeinA+09,
 
@inproceedings{skeinA+09,
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}
 
}
 
</bibtex>
 
</bibtex>
−
 
 
<bibtex>
 
<bibtex>
 
@misc{SkeinAum09,
 
@misc{SkeinAum09,

Latest revision as of 12:26, 2 October 2012

1 The algorithm


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

,2010
http://www.skein-hash.info/sites/default/files/skein1.3.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 : 2010

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/skein1.1.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-256 and 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
collision 256 2 rounds 285 - Khovratovich
collision 256 12 rounds 2126.5 - Khovratovich
collision 512 5 rounds 2192 - Khovratovich
collision 512 14 rounds 2254.5 - Khovratovich
preimage 512 22 rounds 2511.0 26 Khovratovich,Rechberger,Savelieva
preimage 512 72 rounds 2511.76 - Khovratovich,Rechberger,Savelieva


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
preimage compression function 512 22 rounds 2508 26 Khovratovich,Rechberger,Savelieva
preimage compression function 512 37 rounds 2511.2 264 Khovratovich,Rechberger,Savelieva
distinguisher compression function 512 32 rounds 2104.5 - Yu,Chen,Wang
distinguisher compression function 512 36 rounds 2454 - Yu,Chen,Wang
key recovery block cipher 512 32 rounds 2181 - Yu,Chen,Wang
key recovery block cipher 512 34 rounds 2424 - Yu,Chen,Wang
near-collision compression function 256 32 rounds 2105 - Yu,Chen,Jia,Wang
distinguisher compression function all 57 rounds (Round 2) 2503 - Khovratovich,Nikolić,Rechberger
distinguisher compression function 256 53 rounds (Round 2) 2251, Skein-256 - Khovratovich,Nikolić,Rechberger
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



Dmitry Khovratovich - Bicliques for permutations: collision and preimage attacks in stronger settings

,2012
http://eprint.iacr.org/2012/141.pdf
Bibtex
Author : Dmitry Khovratovich
Title : Bicliques for permutations: collision and preimage attacks in stronger settings
In : -
Address :
Date : 2012

Dmitry Khovratovich, Christian Rechberger, Alexandra Savelieva - Bicliques for Preimages: Attacks on Skein-512 and the SHA-2 family

Fast Software Encryption (FSE) ,2012
http://eprint.iacr.org/2011/286.pdf
Bibtex
Author : Dmitry Khovratovich, Christian Rechberger, Alexandra Savelieva
Title : Bicliques for Preimages: Attacks on Skein-512 and the SHA-2 family
In : Fast Software Encryption (FSE) -
Address :
Date : 2012

Hongbo Yu, Jiazhe Chen, Xiaoyun Wang - The Boomerang Attacks on the Round-Reduced Skein-512

,2012
http://eprint.iacr.org/2012/238.pdf
Bibtex
Author : Hongbo Yu, Jiazhe Chen, Xiaoyun Wang
Title : The Boomerang Attacks on the Round-Reduced Skein-512
In : -
Address :
Date : 2012

Hongbo Yu, Jiazhe Chen, Ketingjia, Xiaoyun Wang - Near-Collision Attack on the Step-Reduced Compression Function of Skein-256

,2011
http://eprint.iacr.org/2011/148.pdf
Bibtex
Author : Hongbo Yu, Jiazhe Chen, Ketingjia, Xiaoyun Wang
Title : Near-Collision Attack on the Step-Reduced Compression Function of Skein-256
In : -
Address :
Date : 2011

Dmitry Khovratovich, Ivica Nikolić, Christian Rechberger - Rotational Rebound Attacks on Reduced Skein

ASIACRYPT 6477:1-19,2010
http://eprint.iacr.org/2010/538.pdf
Bibtex
Author : Dmitry Khovratovich, Ivica Nikolić, Christian Rechberger
Title : Rotational Rebound Attacks on Reduced Skein
In : ASIACRYPT -
Address :
Date : 2010

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

CANS 6467:124-139,2010
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 : CANS -
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

Dmitry Khovratovich, Ivica Nikolic - Rotational Cryptanalysis of ARX

FSE 6147:333-346
http://cryptolux.org/mediawiki/uploads/5/5b/Rotational_Cryptanalysis_of_Skein.pdf
Bibtex
Author : Dmitry Khovratovich, Ivica Nikolic
Title : Rotational Cryptanalysis of ARX
In : FSE -
Address :
Date :

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

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

ASIACRYPT 5912:542-559,2009
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 : ASIACRYPT -
Address :
Date : 2009

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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