SHA-1

1 General

• digest size: 160 bits
• max. message length: < 2⁶⁴ bits
• type: iterative hash function
• compression function: 512-bit message block, 160-bit chaining variable
• Specification: FIPS 180-2 Secure Hash Standard

2 Cryptanalysis

2.1 Best Known Results

The best collision attack on full SHA-1 was published by Wang etal. It has complexity of 2⁶⁹ hash evaluations. The best collision example, a 64-step collision for SHA-1, was publshed by DeCanniere and Rechberger.

2.2 Collision Attacks

Mitsuhiro HATTORI, Shoichi HIROSE, Susumu YOSHIDA - Complexity of the Collision and Near-Collision Attack on SHA-0 with Different Message Schedules

,2004

http://eprint.iacr.org/
Bibtex

Author : Mitsuhiro HATTORI, Shoichi HIROSE, Susumu YOSHIDA
Title : Complexity of the Collision and Near-Collision Attack on SHA-0 with Different Message Schedules
In : -
Address :
Date : 2004

Daewan Han, Sangwoo Park, Seongtaek Chee - Cryptanalysis of the Modified Version of the Hash Function Proposed at PKC'98.

Fast Software Encryption 2002 2365:252-262,2002

Bibtex

Author : Daewan Han, Sangwoo Park, Seongtaek Chee
Title : Cryptanalysis of the Modified Version of the Hash Function Proposed at PKC'98.
In : Fast Software Encryption 2002 -
Address :
Date : 2002

Hans Dobbertin - {Cryptanalysis Of MD4}

Journal of Cryptology 11(4):253--271,1998

Bibtex

Author : Hans Dobbertin
Title : {Cryptanalysis Of MD4}
In : Journal of Cryptology -
Address :
Date : 1998

Alfred J. Menezes, Paul C. van Oorschot, Scott A. Vanstone - Handbook of Applied Cryptography

CRC Press,1997

Bibtex

Author : Alfred J. Menezes, Paul C. van Oorschot, Scott A. Vanstone
Title : Handbook of Applied Cryptography
In : -
Address :
Date : 1997

Here I would list all papers that deal with SHA-1. We should also give the abstract and the bibtex entry for the corresponding paper. Additionall we should give our opinion about the attack described in the paper.

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2.3 Second Preimage Attacks

• There exists a generic attack (works for all iterated hash functions). See ....

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2.4 Preimage Attacks

• We are not aware of any article regarding preimage attacks on SHA-1.

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3 Performance Evaluation / Implementation (HW and SW)

Yong Ki Lee, Herwin Chan, Ingrid Verbauwhede - Throughput Optimized SHA-1 Architecture Using Unfolding Transformation.

ASAP 2006 pp. 354-359,2006

http://doi.ieeecomputersociety.org/10.1109/ASAP.2006.68
Bibtex

Author : Yong Ki Lee, Herwin Chan, Ingrid Verbauwhede
Title : Throughput Optimized SHA-1 Architecture Using Unfolding Transformation.
In : ASAP 2006 -
Address :
Date : 2006

4 eHash Recommendation (optional) or eHash Opinion

Something like: SHA-1 is considered to be broken. Please do not incorporate SHA-1 in new application any longer. Try to migrate to another hash function.