Anubis is a

block cipher In cryptography, a block cipher is a deterministic algorithm operating on fixed-length groups of bits, called ''blocks''. Block ciphers are specified cryptographic primitive, elementary components in the design of many cryptographic protocols and ...

Vincent Rijmen Vincent Rijmen (; born 16 October 1970) is a Belgian cryptographer and one of the two designers of the Rijndael, the Advanced Encryption Standard. Rijmen is also the co-designer of the WHIRLPOOL cryptographic hash function, and the block cipher ...

and

Paulo S. L. M. Barreto Paulo S. L. M. Barreto (born 1965) is a Brazilian cryptographer and one of the designers of the Whirlpool (algorithm), Whirlpool cryptographic hash function, hash function and the block ciphers Anubis (cipher), Anubis and KHAZAD, together with Vin ...

as an entrant in the

NESSIE NESSIE (New European Schemes for Signatures, Integrity and Encryption) was a European research project funded from 2000 to 2003 to identify secure cryptographic primitives. The project was comparable to the NIST AES process and the Japanese Gov ...

project, a former research program initiated by the

European Commission The European Commission (EC) is the executive of the European Union (EU). It operates as a cabinet government, with 27 members of the Commission (informally known as "Commissioners") headed by a President. It includes an administrative body o ...

in 2000 for the identification of new

cryptographic Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or '' -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adve ...

algorithms. Although the cipher has not been included in the final NESSIE portfolio, its design is considered very strong, and no attacks have been found by 2004 after the project had been concluded. The cipher is not patented and has been released by the designers for free public use. Anubis operates on data blocks of 128 bits, accepting keys of length 32''N'' bits (''N'' = 4, ..., 10). It is designed as a substitution–permutation network, which bears large similarity to Rijndael. Like

KHAZAD In cryptography, KHAZAD is a block cipher designed by Paulo S. L. M. Barreto together with Vincent Rijmen, one of the designers of the Advanced Encryption Standard ( Rijndael). KHAZAD is named after Khazad-dûm, the fictional dwarven realm in t ...

, designed by the same authors and also submitted to NESSIE, it uses

involution Involution may refer to: * Involute, a construction in the differential geometry of curves * '' Agricultural Involution: The Processes of Ecological Change in Indonesia'', a 1963 study of intensification of production through increased labour inpu ...

s for the various operations. An involution is an operation whose inverse is the same as the forward operation. In other words, when an involution is run twice, it is the same as performing no operation. This allows low-cost hardware and compact software implementations to use the same operations for both encryption and decryption. Both the

S-box In cryptography, an S-box (substitution-box) is a basic component of symmetric key algorithms which performs substitution. In block ciphers, they are typically used to obscure the relationship between the key and the ciphertext, thus ensuring Sha ...

and the mix columns operations are involutions. Although many involutional components can make a cipher more susceptible to

distinguishing attack In cryptography, a distinguishing attack is any form of cryptanalysis on data encrypted by a cipher that allows an attacker to distinguish the encrypted data from random data. Modern symmetric-key ciphers are specifically designed to be immune to ...

s exploiting the cycle structure of permutations within the cipher, no attack strategy for the Anubis cipher has been presented. There are two versions of the Anubis cipher; the original implementation uses a pseudo-random S-box. Subsequently, the S-box was modified to be more efficient to implement in hardware; the newer version of Anubis is called the "tweaked" version. The authors claim the algorithm to be secure against a number of attacks, including four-round differential and linear analysis, as well as related-key,

interpolation In the mathematical field of numerical analysis, interpolation is a type of estimation, a method of constructing (finding) new data points based on the range of a discrete set of known data points. In engineering and science, one often has a n ...

boomerang A boomerang () is a thrown tool, typically constructed with aerofoil sections and designed to spin about an axis perpendicular to the direction of its flight. A returning boomerang is designed to return to the thrower, while a non-returning b ...

, truncated differential, impossible differential, and saturation attacks. Nonetheless, because of the cipher's similarity with Rijndael it was not considered to offer any convincing advantages and thus was not included in the second evaluation phase of the NESSIE project. Anubis is named after the

Egyptian god Ancient Egyptian deities are the gods and goddesses worshipped in ancient Egypt. The beliefs and rituals surrounding these gods formed the core of ancient Egyptian religion, which emerged sometime in prehistory. Deities represented natural fo ...

of entombing and embalming, which the designers interpreted to include

encryption In cryptography, encryption is the process of encoding information. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. Ideally, only authorized parties can decip ...

. They claim that violators of the cipher will be

curse A curse (also called an imprecation, malediction, execration, malison, anathema, or commination) is any expressed wish that some form of adversity or misfortune will befall or attach to one or more persons, a place, or an object. In particular, ...

References

External links

The ANUBIS Block Cipher
by Paulo S. L. M. Barreto

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