In cryptography, ABC is a block cipher designed in 2002 by Dieter Schmidt. In cryptography, MMB (Modular Multiplication-based Block cipher) is a block cipher designed by Joan Daemen as an improved replacement for the IDEA cipher. ... This article is about the encryption algorithm. ... In cryptography, the key size (alternatively key length) is a measure of the number of possible keys which can be used in a cipher. ... In modern cryptography, symmetric key ciphers are generally divided into stream ciphers and block ciphers. ... In cryptography, an SP-network, or substitution-permutation network (SPN), is a series of linked mathematical operations used in block cipher algorithms such as AES. These networks consist of S-boxes and P-boxes that transform blocks of input bits into output bits. ... The German Lorenz cipher machine, used in World War II for encryption of very high-level general staff messages Cryptography (or cryptology; derived from Greek κρυπτός kryptós hidden, and the verb γράφω gráfo write) is the study of message secrecy. ... Encryption Decryption In cryptography, a block cipher is a symmetric key cipher which operates on fixed-length groups of bits, termed blocks, with an unvarying transformation. ...

ABC is a substitution-permutation network comprising 17 rounds with 3 different kinds of round functions. The first 8 rounds use XORs, modular multiplications as in MMB, and an expanded version of the pseudo-Hadamard transform (PHT) from SAFER. The middle round uses just XORs and multiplications. The final 8 rounds are similar to the first 8, but using the inverse PHT. ABC's block size of 256 bits and key size of 512 bits are both larger than in typical block cipher algorithms. The key schedule is very simple: 256-bit round keys are taken from the key, which is rotated by a fixed amount in each round. In cryptography, an SP-network, or substitution-permutation network (SPN), is a series of linked mathematical operations used in block cipher algorithms such as AES. These networks consist of S-boxes and P-boxes that transform blocks of input bits into output bits. ... Exclusive disjunction (usual symbol xor) is a logical operator that results in true if one of the operands (not both) is true. ... Modular arithmetic (sometimes called modulo arithmetic) is a system of arithmetic for integers, where numbers wrap around after they reach a certain value — the modulus. ... In cryptography, MMB (Modular Multiplication-based Block cipher) is a block cipher designed by Joan Daemen as an improved replacement for the IDEA cipher. ... The Pseudo-Hadamard transform is a reversible transformation of a bit string that provides cryptographic diffusion. ... This article is about the encryption algorithm. ... In modern cryptography, symmetric key ciphers are generally divided into stream ciphers and block ciphers. ... In cryptography, the key size (alternatively key length) is a measure of the number of possible keys which can be used in a cipher. ... The key-schedule of DES In cryptography, the algorithm for computing the subkeys for each round in a product cipher from the encryption (or decryption) key is called the key schedule. ... A key is a piece of information that controls the operation of a cryptography algorithm. ...

References

• Dieter Schmidt (2002-05-27). "ABC - A Block Cipher" (PDF/PostScript). Retrieved on 2007-01-21.