MD4

1 Specification

• digest size: 128 bits
• max. message length: < 2⁶⁴ bits
• compression function: 512-bit message block, 128-bit chaining variable
• Specification:

Ronald L. Rivest - The MD4 Message Digest Algorithm

CRYPTO 537:303-311,1990

http://link.springer.de/link/service/series/0558/bibs/0537/05370303.htm
Bibtex

Author : Ronald L. Rivest
Title : The MD4 Message Digest Algorithm
In : CRYPTO -
Address :
Date : 1990

2 Cryptanalysis

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2.2 Generic Attacks

• Generic Attacks on the Merkle-Damgaard Construction

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2.3 Collision Attacks

@inproceedings{fseSasakiWOK07,

 author    = {Yu Sasaki and Lei Wang and Kazuo Ohta and Noboru Kunihiro},
 title     = {New Message Difference for MD4},
 pages     = {329-348},
 url        = {http://dx.doi.org/10.1007/978-3-540-74619-5_21},
 editor    = {Alex Biryukov},
 booktitle = {FSE},
 publisher = {Springer},
 series    = {LNCS},
 volume    = {4593},
 year      = {2007},
 isbn      = {978-3-540-74617-1},
 abstract  = {This paper proposes several approaches to improve 

the collision attack on MD4 proposed by Wang et al. First, we propose a new local collision that is the best for the MD4 collision attack. Selection of a good message difference is the most important step in achieving effective collision attacks. This is the first paper to introduce an improvement to the message difference approach of Wang et al., where we propose a new local collision. Second, we propose a new algorithm for constructing differential paths. While similar algorithms have been proposed, they do not support the new local collision technique.Finally, we complete a collision attack, and show that the complexity is smaller than the previous best work.} } </bibtex>

Gaëtan Leurent - Message Freedom in MD4 and MD5 Collisions: Application to APOP

FSE 4593:309-328,2007

http://dx.doi.org/10.1007/978-3-540-74619-5_20
Bibtex

Author : Gaëtan Leurent
Title : Message Freedom in MD4 and MD5 Collisions: Application to APOP
In : FSE -
Address :
Date : 2007

Xiaoyun Wang, Xuejia Lai, Dengguo Feng, Hui Chen, Xiuyuan Yu - Cryptanalysis of the Hash Functions MD4 and RIPEMD

EUROCRYPT 3494:1-18,2005

http://dx.doi.org/10.1007/11426639_1
Bibtex

Author : Xiaoyun Wang, Xuejia Lai, Dengguo Feng, Hui Chen, Xiuyuan Yu
Title : Cryptanalysis of the Hash Functions MD4 and RIPEMD
In : EUROCRYPT -
Address :
Date : 2005

Hans Dobbertin - Cryptanalysis of MD4

J. Cryptology 11(4):253-271,1998

http://link.springer.de/link/service/journals/00145/bibs/11n4p253.html
Bibtex

Author : Hans Dobbertin
Title : Cryptanalysis of MD4
In : J. Cryptology -
Address :
Date : 1998

Hans Dobbertin - Cryptanalysis of MD4

FSE 1039:53-69,1996

http://dx.doi.org/10.1007/s001459900047
Bibtex

Author : Hans Dobbertin
Title : Cryptanalysis of MD4
In : FSE -
Address :
Date : 1996

Serge Vaudenay - On the Need for Multipermutations: Cryptanalysis of MD4 and SAFER

FSE 1008:286-297,1995

http://dx.doi.org/10.1007/3-540-60590-8_22
Bibtex

Author : Serge Vaudenay
Title : On the Need for Multipermutations: Cryptanalysis of MD4 and SAFER
In : FSE -
Address :
Date : 1995

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2.5 Preimage Attacks

Hans Dobbertin - The First Two Rounds of MD4 are Not One-Way

FSE 1372:284-292,1998

http://dx.doi.org/10.1007/3-540-69710-1_19
Bibtex

Author : Hans Dobbertin
Title : The First Two Rounds of MD4 are Not One-Way
In : FSE -
Address :
Date : 1998

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2.6 Others

<bibtex> @inproceedings{fseSchlafferO06,

 author    = {Martin Schläffer and Elisabeth Oswald},
 title     = {Searching for Differential Paths in MD4},
 pages     = {242-261},
 url        = {http://dx.doi.org/10.1007/11799313_16},
 booktitle = {FSE},
 publisher = {Springer},
 series    = {LNCS},
 volume    = {4047},
 year      = {2006},
 isbn      = {3-540-36597-4},
 abstract  = {The ground-breaking results of Wang et al. 

have attracted a lot of attention to the collision resistance of hash functions. In their articles, Wang et al. give input differences, differential paths and the corresponding conditions that allow to find collisions with a high probability. However, Wang et al. do not explain how these paths were found. The common assumption is that they were found by hand with a great deal of intuition. In this article, we present an algorithm that allows to find paths in an automated way. Our algorithm is successful for MD4. We have found over 1000 differential paths so far. Amongst them, there are paths that have fewer conditions in the second round than the path of Wang et al. for MD4. This makes them better suited for the message modification techniques that were also introduced by Wang et al.} }