Difference between revisions of "MD4"

From The ECRYPT Hash Function Website
(Collision Attacks)
(Collision Attacks)
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=== Collision Attacks ===
 
=== Collision Attacks ===
 +
<bibtex>
 +
@inproceedings{fseLeurent07,
 +
  author    = {Ga&euml;tan Leurent},
 +
  title    = {Message Freedom in MD4 and MD5 Collisions: Application to APOP},
 +
  pages    = {309-328},
 +
  url        = {http://dx.doi.org/10.1007/978-3-540-74619-5_20},
 +
  editor    = {Alex Biryukov},
 +
  booktitle = {FSE},
 +
  publisher = {Springer},
 +
  series    = {LNCS},
 +
  volume    = {4593},
 +
  year      = {2007},
 +
  isbn      = {978-3-540-74617-1},
 +
  abstract  = {In Wang’s attack, message modifications allow to
 +
deterministically satisfy certain sufficient conditions to find
 +
collisions efficiently. Unfortunately, message modifications
 +
significantly change the messages and one has little control
 +
over the colliding blocks. In this paper, we show how to choose
 +
small parts of the colliding messages. Consequently, we break a
 +
security countermeasure proposed by Szydlo and Yin at CT-RSA ’06,
 +
where a fixed padding is added at the end of each block. Furthermore,
 +
we also apply this technique to recover part of the passwords in the
 +
Authentication Protocol of the Post Office Protocol (POP). This shows
 +
that collision attacks can be used to attack real protocols, which means that finding collisions is a real threat.}
 +
}
 +
</bibtex>
  
 
<bibtex>
 
<bibtex>

Revision as of 12:12, 11 March 2008

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

2.1 Best Known Results


2.2 Generic Attacks


2.3 Collision Attacks

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

2.4 Second Preimage Attacks


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

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.} }