ПРОГРАМНА BITSLICED-ІМПЛЕМЕНТАЦІЯ ШИФРУ «КАЛИНА» ОРІЄНТОВАНА НА ВИКОРИСТАННЯ SIMD-ІНСТРУКЦІЙ МІКРОПРОЦЕСОРІВ З АРХІТЕКТУРОЮ Х86-64

Abstract

The article is devoted to software bitsliced implementation of the Kalyna cipher using vector instructions SSE, AVX, AVX-512 for x86-64 processors. The advantages and disadvantages of different approaches to efficient and secure block cipher software implementation are shown. It is noted that bitslicing technology combines high speed and resistance to time and cache attacks, but its application to the Kalyna cipher is not available at the moment. The basic approaches to data representation and bitsliced encryption operations are considered, special attention is paid to the effective implementation of SubBytes operation, which largely determines the final performance. Existing methods for minimizing logical functions have been shown to either fail to produce the result in bitsliced format in the case of 8-bit non-algebraic SBoxs, or far from optimal. A heuristic algorithm for minimizing logic functions describing Kalyna SBoxes using the operations of AND, OR, XOR, NOT available in the instruction set of low- and high-end processors is proposed. The results show that a bitsliced description of one SBox requires about 520 gates, which is significantly less than other methods. Possible ways to increase performance by regrouping data into bitsliced variables before and after the SubBytes operation are indicated, which results in more efficient use of vector registers. The bitsliced implementations of Kalyna cipher were measured using C++ compilers from Microsoft and GCC for the Intel Xeon Skylake-SP processor. The results of the bitsliced Kalyna implementation can also be transferred to processors that do not support SIMD instructions, including low-end, to increase resistance to attacks through third-party channels. They also enable switching to ASIC or FPGA-based bitsliced implementation of Kalyna.