|
Kalyna (cipher)
Kalyna (Ukrainian language, Ukrainian: Калина, Viburnum opulus) is a symmetric block cipher. It supports block sizes of 128, 256 or 512 bits; the key length is either equal to or double the block size. Kalyna was adopted as the national encryption standard of Ukraine in 2015 (standard DSTU 7624:2014) after holding Ukrainian national cryptographic competition. Kalyna is a substitution–permutation network and its design is based on the Advanced Encryption Standard, Rijndael (AES) encryption function having quite different key schedule, another set of four different S-boxes and increased MDS matrix size. Kalyna has 10 rounds for 128-bit keys, 14 rounds for 256-bit keys and 18 rounds for 512-bit keys. Independent researchers proposed some attacks on reduced-round variants of Kalyna, but all of them have a very high complexity and none of them are practical. References * Roman Oliynykov, Ivan Gorbenko, Oleksandr Kazymyrov, Victor Ruzhentsev, Oleksandr Kuznetsov, Yurii G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MDS Matrix
An MDS matrix (maximum distance separable) is a matrix representing a function with certain diffusion properties that have useful applications in cryptography. Technically, an m \times n matrix A over a finite field K is an MDS matrix if it is the transformation matrix of a linear transformation f(x) = Ax from K^n to K^m such that no two different (m + n)-tuples of the form (x, f(x)) coincide in n or more components. Equivalently, the set of all (m + n)-tuples (x, f(x)) is an MDS code, i.e., a linear code that reaches the Singleton bound. Let \tilde A = \begin \mathrm_n \\ \hline \mathrm \end be the matrix obtained by joining the identity matrix \mathrm_n to A. Then a necessary and sufficient condition for a matrix A to be MDS is that every possible n \times n submatrix obtained by removing m rows from \tilde A is non-singular. This is also equivalent to the following: all the sub-determinants of the matrix A are non-zero. Then a binary matrix A (namely over the field with two el ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |