RIPEMD - Revision history

Fmendel: /* Collision Attacks */

2008-03-11T16:19:52Z

‎Collision Attacks

Fmendel: /* Best Known Results */

2008-03-11T16:18:53Z

‎Best Known Results

Fmendel: /* Best Known Results */

2008-03-11T16:18:17Z

‎Best Known Results

Mlamberger: /* Collision Attacks */

2008-03-11T10:11:22Z

‎Collision Attacks

Tnad: /* Collision Attacks */

2008-03-10T17:39:42Z

‎Collision Attacks

Fmendel: /* Collision Attacks */

2008-03-10T16:10:15Z

‎Collision Attacks

Fmendel at 16:03, 10 March 2008

2008-03-10T16:03:36Z

Fmendel at 16:02, 10 March 2008

2008-03-10T16:02:30Z

Tnad: /* Spezification */

2008-03-10T15:01:18Z

‎Spezification

Fmendel at 13:34, 7 March 2008

2008-03-07T13:34:33Z

@@ Line 30: / Line 30: @@
    year = {2005},
    pages = {1-18},
-   abstract = {MD4 is a hash function developed by Rivest in 1990. It serves as the basis for most of the dedicated hash functions such as MD5, SHAx, RIPEMD, and HAVAL. In 1996, Dobbertin showed how to find collisions of MD4 with complexity equivalent to 220 MD4 hash computations. In this paper, we present a new attack on MD4 which can find a collision with probability 2–2 to 2–6, and the complexity of finding a collision doesnrsquot exceed 28 MD4 hash operations. Built upon the collision search attack, we present a chosen-message pre-image attack on MD4 with complexity below 28. Furthermore, we show that for a weak message, we can find another message that produces the same hash value. The complexity is only a single MD4 computation, and a random message is a weak message with probability 2–122. The attack on MD4 can be directly applied to RIPEMD which has two parallel copies of MD4, and the complexity of finding a collision is about 218 RIPEMD hash operations.},
+   abstract = {MD4 is a hash function developed by Rivest in 1990. It serves as the basis for most of the dedicated hash functions such as MD5, SHAx, RIPEMD, and HAVAL. In 1996, Dobbertin showed how to find collisions of MD4 with complexity equivalent to 2^{20} MD4 hash computations. In this paper, we present a new attack on MD4 which can find a collision with probability 2^{–2} to 2^{–6}, and the complexity of finding a collision doesnrsquot exceed 2^8 MD4 hash operations. Built upon the collision search attack, we present a chosen-message pre-image attack on MD4 with complexity below 2^8. Furthermore, we show that for a weak message, we can find another message that produces the same hash value. The complexity is only a single MD4 computation, and a random message is a weak message with probability 2^{–122}. The attack on MD4 can be directly applied to RIPEMD which has two parallel copies of MD4, and the complexity of finding a collision is about 2^{18} RIPEMD hash operations.},
    editor = {Ronald Cramer},
    volume = {3494},

@@ Line 12: / Line 12: @@
 === Best Known Results ===
-The best collision attack on full RIPEMD was published by Wang et al. It has complexity of 2<sup></sup> hash evaluations.
+The best collision attack on full RIPEMD was published by Wang et al. It has complexity of 2<sup>18</sup> hash evaluations.
 ----

← Older revision		Revision as of 16:18, 11 March 2008
Line 12:		Line 12:

	=== Best Known Results ===		=== Best Known Results ===
		+	The best collision attack on full RIPEMD was published by Wang et al. It has complexity of 2<sup></sup> hash evaluations.

	----		----

@@ Line 21: / Line 21: @@
 === Collision Attacks ===
 <bibtex>
 @inproceedings{fseDebaertG01,

← Older revision		Revision as of 17:39, 10 March 2008
Line 21:		Line 21:

	=== Collision Attacks ===		=== Collision Attacks ===
		+	<bibtex>
		+	@inproceedings{fseDebaertG01,
		+	author = {Christophe Debaert and Henri Gilbert},
		+	title = {The RIPEMD and RIPEMD Improved Variants of MD4 Are Not Collision Free},
		+	pages = {52-65},
		+	url = {http://link.springer.de/link/service/series/0558/bibs/2355/23550052.htm},
		+	editor = {Mitsuru Matsui},
		+	booktitle = {FSE},
		+	publisher = {Springer},
		+	series = {LNCS},
		+	volume = {2355},
		+	year = {2002},
		+	isbn = {3-540-43869-6},
		+	abstract = {In 1992, the cryptographic hash function RIPEMD, a European proposal, was introduced as an improved variant of the MD4 hash function. RIPEMD involves two parallel lines of modified versions of the MD4 compression function. Three years later, an attack against a reduced version of RIPEMD in which the first or the last round of the RIPEMD compression function is omitted was described by Hans Dobbertin, who also published in 1998 a cryptanalysis of MD4. In this paper, we present a method for finding collisions in each of the parallel lines of RIPEMD. The collision search procedure requires only a few seconds computing time. We show that although the modifications of the MD4 compression function Used in RIPEMD introduce additional constraints in the cryptanalysis as Compared with Dobbertin’s attack of MD4, these modifications do not result in an increase of the collision search computation time. It is still an open question whether collisions can be found for the full RIPEMD function.},
		+	}
		+	</bibtex>

	<bibtex>		<bibtex>

@@ Line 25: / Line 25: @@
 @article{jocDobbertin97,
    author    = {Hans Dobbertin},
-   title     = {{RIPEMD with Two-Round Compress Function is Not Collision-Free}},
+   title     = {RIPEMD with Two-Round Compress Function is Not Collision-Free},
    journal   = {J. Cryptology},
    volume    = {10},

@@ Line 1: / Line 1: @@
 == Specification ==
-<!--
-* digest size: 160 bits
+* digest size: 128 bits
 * max. message length: < 2<sup>64</sup> bits
-* compression function: 512-bit message block, 160-bit chaining variable
+* compression function: 512-bit message block, 2 streams with each 128-bit chaining variable
 * Specification:
--->
 == Cryptanalysis ==

← Older revision		Revision as of 16:02, 10 March 2008
Line 21:		Line 21:

	=== Collision Attacks ===		=== Collision Attacks ===
		+
		+	<bibtex>
		+	@article{jocDobbertin97,
		+	author = {Hans Dobbertin},
		+	title = {{RIPEMD with Two-Round Compress Function is Not Collision-Free}},
		+	journal = {J. Cryptology},
		+	volume = {10},
		+	number = {1},
		+	year = {1997},
		+	pages = {51-70},
		+	url = {http://dx.doi.org/10.1007/s001459900019},
		+	abstract = {In 1990 Rivest introduced the cryptographic hash function MD4. The compress function of MD4 has three rounds. After partial attacks against MD4 were found, the stronger mode RIPEMD was designed as a European proposal in 1992 (RACE project). Its compress function consists of two parallel lines of modified versions of MD4-compress. RIPEMD is currently being considered to become an international standard (ISO/IEC Draft 10118-3). However, in this paper an attack against RIPEMD is described, which leads to comparable results with the previously known attacks against MD4: The reduced versions of RIPEMD, where the first or the last round of the compress function is omitted, are not collision-free. Moreover, it turns out that the methods developed in this note can be applied to find collisions for the full MD4.},
		+	}
		+	</bibtex>

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← Older revision		Revision as of 15:01, 10 March 2008
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−	== ~~Spezification~~ ==	+	== Specification ==

	<!--		<!--

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-== General ==
+== Spezification ==
 <!--
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 === Others ===