Grand Cru (cipher)
Encyclopedia
In cryptography
, Grand Cru is a block cipher
invented in 2000 by Johan Borst. It was submitted to the NESSIE
project, but was not selected.
Grand Cru is a 10-round substitution-permutation network
based largely on Rijndael (or AES). It replaces a number of Rijndael's unkeyed operations with key-dependent ones, in a way consistent with the security purposes of each operation. The intent is to produce a cipher at least as secure as Rijndael, and perhaps much more secure. The block size
and key size
are both 128 bits, and the key schedule
is the same as Rijndael's
.
Grand Cru is designed on the principle of multiple layered security. It is equivalent to a chain of 4 subciphers with independent keys, such that if 3 of the keys are known, the remaining cipher should still be secure.
Cryptography
Cryptography is the practice and study of techniques for secure communication in the presence of third parties...
, Grand Cru is a block cipher
Block cipher
In cryptography, a block cipher is a symmetric key cipher operating on fixed-length groups of bits, called blocks, with an unvarying transformation. A block cipher encryption algorithm might take a 128-bit block of plaintext as input, and output a corresponding 128-bit block of ciphertext...
invented in 2000 by Johan Borst. It was submitted to the NESSIE
NESSIE
NESSIE was a European research project funded from 2000–2003 to identify secure cryptographic primitives. The project was comparable to the NIST AES process and the Japanese Government-sponsored CRYPTREC project, but with notable differences from both...
project, but was not selected.
Grand Cru is a 10-round substitution-permutation network
Substitution-permutation network
In cryptography, an SP-network, or substitution-permutation network , is a series of linked mathematical operations used in block cipher algorithms such as AES .Other ciphers that use SPNs are 3-Way, SAFER, SHARK, and Square....
based largely on Rijndael (or AES). It replaces a number of Rijndael's unkeyed operations with key-dependent ones, in a way consistent with the security purposes of each operation. The intent is to produce a cipher at least as secure as Rijndael, and perhaps much more secure. The block size
Block size (cryptography)
In modern cryptography, symmetric key ciphers are generally divided into stream ciphers and block ciphers. Block ciphers operate on a fixed length string of bits. The length of this bit string is the block size...
and key size
Key size
In cryptography, key size or key length is the size measured in bits of the key used in a cryptographic algorithm . An algorithm's key length is distinct from its cryptographic security, which is a logarithmic measure of the fastest known computational attack on the algorithm, also measured in bits...
are both 128 bits, and the key schedule
Key schedule
[[Image:DES-key-schedule.png|thumbnail|220px|The key schedule of DES [[Image:DES-key-schedule.png|thumbnail|220px|The key schedule of DES [[Image:DES-key-schedule.png|thumbnail|220px|The key schedule of DES ("[[Image:DES-key-schedule.png|thumbnail|220px|The key schedule of DES ("...
is the same as Rijndael's
Rijndael key schedule
AES uses a key schedule to expand a short key into a number of separate round keys. This is known as the Rijndael key schedule.- Common operations :...
.
Grand Cru is designed on the principle of multiple layered security. It is equivalent to a chain of 4 subciphers with independent keys, such that if 3 of the keys are known, the remaining cipher should still be secure.