SHA-256/224

1 Specification

• digest size: 256 bits
• max. message length: < 2⁶⁴ bits
• compression function: 512-bit message block, 256-bit chaining variable
• Specification: FIPS 180-2 Secure Hash Standard

2 Cryptanalysis

2.1 Best Known Results

Collision attacks up to 24 out of 64 steps. Other non random behavior up to 31 steps. Both results are due to Indesteege et al (SAC 2008). Preimages on up to 24 steps due to Isobe and Shibutani (FSE 2009).

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2.2 Generic Attacks

• Generic Attacks on the Merkle-Damgaard Construction

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2.3 Collision Attacks

Sebastiaan Indesteege, Florian Mendel, Bart Preneel, Christian

Rechberger - Collisions and other Non-Random Properties for Step-Reduced SHA-256

Selected Areas in Cryptography -- SAC 2008 5381:276-293,2008

http://dx.doi.org/10.1007/978-3-642-04159-4_18
Bibtex

Author : Sebastiaan Indesteege, Florian Mendel, Bart Preneel, Christian Rechberger
Title : Collisions and other Non-Random Properties for Step-Reduced SHA-256
In : Selected Areas in Cryptography -- SAC 2008 -
Address :
Date : 2008

Somitra Kumar Sanadhya, Palash Sarkar - Deterministic Constructions of 21-Step Collisions for the SHA-2 Hash Family

ISC 5222:244-259,2008

http://dx.doi.org/10.1007/978-3-540-85886-7_17
Bibtex

Author : Somitra Kumar Sanadhya, Palash Sarkar
Title : Deterministic Constructions of 21-Step Collisions for the SHA-2 Hash Family
In : ISC -
Address :
Date : 2008

Somitra Kumar Sanadhya, Palash Sarkar - Non-linear Reduced Round Attacks against SHA-2 Hash Family

ACISP 5107:254-266,2008

http://dx.doi.org/10.1007/978-3-540-70500-0_19
Bibtex

Author : Somitra Kumar Sanadhya, Palash Sarkar
Title : Non-linear Reduced Round Attacks against SHA-2 Hash Family
In : ACISP -
Address :
Date : 2008

Ivica Nikolic, Alex Biryukov - Collisions for Step-Reduced SHA-256

FSE 5086:1-15,2008

http://dx.doi.org/10.1007/978-3-540-71039-4_1
Bibtex

Author : Ivica Nikolic, Alex Biryukov
Title : Collisions for Step-Reduced SHA-256
In : FSE -
Address :
Date : 2008

Somitra Kumar Sanadhya, Palash Sarkar - New Local Collisions for the SHA-2 Hash Family

ICISC 4817:193-205,2007

http://dx.doi.org/10.1007/978-3-540-76788-6_16
Bibtex

Author : Somitra Kumar Sanadhya, Palash Sarkar
Title : New Local Collisions for the SHA-2 Hash Family
In : ICISC -
Address :
Date : 2007

Florian Mendel, Norbert Pramstaller, Christian Rechberger, Vincent Rijmen - Analysis of Step-Reduced SHA-256

FSE 4047:126-143,2006

http://dx.doi.org/10.1007/11799313_9
Bibtex

Author : Florian Mendel, Norbert Pramstaller, Christian Rechberger, Vincent Rijmen
Title : Analysis of Step-Reduced SHA-256
In : FSE -
Address :
Date : 2006

Hirotaka Yoshida, Alex Biryukov - Analysis of a SHA-256 Variant

Selected Areas in Cryptography 3897:245-260,2005

http://dx.doi.org/10.1007/11693383_17
Bibtex

Author : Hirotaka Yoshida, Alex Biryukov
Title : Analysis of a SHA-256 Variant
In : Selected Areas in Cryptography -
Address :
Date : 2005

Henri Gilbert, Helena Handschuh - Security Analysis of SHA-256 and Sisters

Selected Areas in Cryptography 3006:175-193,2003

http://springerlink.metapress.com/openurl.asp?genre=article{\&}issn=0302-9743{\&}volume=3006{\&}spage=175
Bibtex

Author : Henri Gilbert, Helena Handschuh
Title : Security Analysis of SHA-256 and Sisters
In : Selected Areas in Cryptography -
Address :
Date : 2003

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2.5 Preimage Attacks

Takanori Isobe, Kyoji Shibutani - Preimage Attacks on Reduced Tiger and SHA-2

Fast Software Encryption -- FSE 2009 5665:139-155,2009

http://dx.doi.org/10.1007/978-3-642-03317-9
Bibtex

Author : Takanori Isobe, Kyoji Shibutani
Title : Preimage Attacks on Reduced Tiger and SHA-2
In : Fast Software Encryption -- FSE 2009 -
Address :
Date : 2009

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