HAVAL is a
cryptographic hash function
A cryptographic hash function (CHF) is a hash algorithm (a map (mathematics), map of an arbitrary binary string to a binary string with a fixed size of n bits) that has special properties desirable for a cryptography, cryptographic application: ...
. Unlike
MD5
The MD5 message-digest algorithm is a widely used hash function producing a 128-bit hash value. MD5 was designed by Ronald Rivest in 1991 to replace an earlier hash function MD4, and was specified in 1992 as Request for Comments, RFC 1321.
MD5 ...
, but like most modern cryptographic hash functions, HAVAL can produce hashes of different lengths – 128 bits, 160 bits, 192 bits, 224 bits, and 256 bits. HAVAL also allows users to specify the number of rounds (3, 4, or 5) to be used to generate the hash. HAVAL was broken in 2004.
HAVAL was invented by
Yuliang Zheng
Yuliang Zheng, Ph.D., is Professor and Chair of thDepartment of Computer Scienceat the University of Alabama at Birmingham. He is best known for inventing the signcryption
In cryptography, signcryption is a public-key primitive that simultaneously ...
,
Josef Pieprzyk
Josef Pieprzyk (born 1949 in Poland) is currently a professor at Queensland University of Technology in Brisbane, Australia.
He has worked on cryptography, in particular the XSL attack. He collaborated in the invention of the LOKI and LOKI97 b ...
, and
Jennifer Seberry
Jennifer Roma Seberry (also published as Jennifer Seberry Wallis; born 13 February 1944 in Sydney) is an Australian cryptographer, mathematician, and computer scientist, currently a professor at the University of Wollongong, Australia. She was f ...
in 1992.
HAVAL hashes
The HAVAL hashes (also termed ''fingerprints'') are typically represented as 32-, 40-, 48-, 56- or 64-digit
hexadecimal
Hexadecimal (also known as base-16 or simply hex) is a Numeral system#Positional systems in detail, positional numeral system that represents numbers using a radix (base) of sixteen. Unlike the decimal system representing numbers using ten symbo ...
numbers. The following demonstrates a 43-byte
ASCII
ASCII ( ), an acronym for American Standard Code for Information Interchange, is a character encoding standard for representing a particular set of 95 (English language focused) printable character, printable and 33 control character, control c ...
input and the corresponding HAVAL hash (256 bits, 5 passes):
HAVAL("The quick brown fox jumps over the lazy og", 256, 5) =
b89c551cdfe2e06dbd4cea2be1bc7d557416c58ebb4d07cbc94e49f710c55be4
Even a small change in the message will (with overwhelming probability) result in a completely different hash, e.g. changing the letter to a produces the following hash value:
HAVAL("The quick brown fox jumps over the lazy og", 256, 5) =
60983bb8c8f49ad3bea29899b78cd741f4c96e911bbc272e5550a4f195a4077e
The hash of a zero-length string is:
HAVAL("", 256, 5) =
be417bb4dd5cfb76c7126f4f8eeb1553a449039307b1a3cd451dbfdc0fbbe330
Security
Research has uncovered weaknesses which make further use of HAVAL (at least the variant with 128 bits and 3 passes with 2
6 operations) questionable. On 17 August 2004,
collision
In physics, a collision is any event in which two or more bodies exert forces on each other in a relatively short time. Although the most common use of the word ''collision'' refers to incidents in which two or more objects collide with great for ...
s for HAVAL (128 bits, 3 passes) were announced by
Xiaoyun Wang
Wang Xiaoyun (; born 1966) is a Chinese cryptographer, mathematician, and computer scientist. She is a professor in the Department of Mathematics and System Science of Shandong University and an academician of the Chinese Academy of Sciences.
...
, Dengguo Feng,
Xuejia Lai
Xuejia Lai () is a cryptographer, currently a professor at Shanghai Jiao Tong University. His notable work includes the design of the block cipher IDEA based on the Lai-Massey scheme, the theory of Markov ciphers, and the cryptanalysis of a numb ...
, and Hongbo Yu.
Collisions for Hash Functions MD4, MD5, HAVAL-128 and RIPEMD
/ref>
See also
* Hash function security summary
This article summarizes publicly known attacks against cryptographic hash functions. Note that not all entries may be up to date. For a summary of other hash function parameters, see comparison of cryptographic hash functions.
Table color key
...
References
External links
HAVAL
(the official HAVAL page with the research paper on HAVAL, the latest C source code and HAVAL OIDs)
Cryptographic hash functions
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