The triple-DES-96 cryptographic system
Víctor Manuel Silva-García, Rolando Flores-Carapia, Carlos Rentería-Márquez, B. Luna-Benoso · International Journal of Contemporary Mathematical Sciences · 2013
This paper proposes a variant of the Triple-DES cryptosystem; the latter, has a 64-bits block input according to the international standard, FIPS PUB 146-3. However, the Triple-DES cryptosystem input blocks can be extended from 64 to 96 bits without losing computational complexity, especially before a brute force attack. This change incorporates a modification to Triple-DES cryptosystems that appears in more recent systems as Advanced Encryption Standard (AES), FIPS PUB 926 V. M. Silva Grcia et al. 197. As a permutation is removed from the Triple-DES system and the length of the input block is increased, it has as a result Triple-DES-96 encryption consuming time in less than half the time used by Triple DES, that is, if a M file is encrypted (with m ≈ 61.44 Mb or bigger) using the Triple-DES system and runs in time t, with the Triple-DES96 cryptosystem it will run in less time than (1/2)t. Developing this new cryptosystem intends to apply the factorial theorem, i.e. any permutation on an array of 96 positions can be built from 3 permutations on arrangements of 64 positions. According to JV Theorem, given a number n with 0 ≤ n ≤ 64!− 1 ≈ 1089, it can associate a permutation with an arrangement of 64 positions in 63 steps. Therefore we can apply a variable permutation on a chain of 96 bits in the Triple-DES-96 cryptosystem at the start of the first cycle third round and its inverse at the entrance of the third cycle fifteenth round, using 3 ni numbers with 0 ≤ n ≤ 1089 for i = 1, 2, 3. This strengthens Triple-DES-96 with respect to Triple-DES. Mathematics Subject Classification: 14G50