Akelarre is a block cipher proposed in 1996, and combined features from IDEA and RC5. It was shown to be susceptible even to a ciphertextonly attack in 2000 (Knudsen and Rijmen, 2000). In cryptography, a block cipher is a type of symmetric key cipher which operates on groups of bits of a fixed length, termed blocks. ...
1996 is a leap year starting on Monday of the Gregorian calendar, and was designated the International Year for the Eradication of Poverty. ...
In cryptography, the International Data Encryption Algorithm (IDEA) is a block cipher designed by Xuejia Lai and James L. Massey of ETHZürich and was first described in 1991. ...
One round (two halfrounds) of the RC5 block cipher RC5 is a block cipher notable for its simplicity. ...
In cryptography, a ciphertextonly attack is a form of cryptanalysis where the attacker is assumed to have access only to a set of ciphertexts. ...
2000 is a leap year starting on Saturday of the Gregorian calendar. ...
Akelarre is a 128bit block cipher with a variable keylength which must be some multiple of 64 bits. The number of rounds is variable, but four are suggested. The round function of Akelarre is similar to IDEA in structure.
References
 Lars Knudsen and Vincent Rijmen, Ciphertextonly Attack on Akelarre, Cryptologia, Vol. 24(2), April 2000, pp135–147.
 G. Álvarez Marañón, A. Fúster Sabater, D. Guía Martínez, F. Montoya Vitini y A. Peinado Domínguez, Akelarre: a New Block Cipher Algorithm, pp1–14, in proceedings of SAC'96, Third Annual Workshop on Selected Areas in Cryptography, Queen's University, Kingston, Ontario, 1996 [1] (http://www.iec.csic.es/~gonzalo/publis/papers/Akelarre.zip).
 Niels Ferguson and Bruce Schneier, Cryptanalysis of Akelarre, Fourth Annual Workshop on Selected Areas in Cryptography, August 1997, pp201–212 (PDF) (http://www.schneier.com/paperakelarre.pdf).
Lars R. Knudsen Lars Ramkilde Knudsen (born February 21, 1962) is a Danish researcher in cryptography, particularly the design and analysis of block ciphers, hash functions and message authentication codes (MACs). ...
Vincent Rijmen (born 16 October 1970) is a cryptographer and one of the designers of the Advanced Encryption Standard. ...
Cryptologia is a journal in cryptography published quarterly since 1977. ...
Bruce Schneier Bruce Schneier (born January 15, 1963) is an American cryptographer, computer security expert, and writer. ...
