Architecture Types of the Bit Permutation Instruction for General Purpose Processors

Abstract

In large information systems different data transform algorithms including the bit permutation operations requiring an execution of great number of cycles are used. To increase significantly the software performance of such algorithm a controlled bit permutation instruction (BPI) is desirable. Here a question of justification of embedding a new command, controlled BPI, into the standard set of instructions of general-purpose processor for increasing the efficiency of different types algorithms implemented in software is studied. In a variety of applications two different types of bit permutation operations are required: arbitrary fixed permutations and variable permutations. The last are used in a new fast cipher designs based on data-dependent permutations. Accounting for an expediency of embedding the controlled permutation command into the set of elementary processor operations the cryptographic applications form only one of the motivation elements. Another strong motivation is BPI’s use for solving variety of non-cryptographic problems. The multipurpose architecture of the BPI operation oriented to the efficient execution of both the cryptographic functions based on data-driven permutations and the algorithms including arbitrary bit permutations is proposed.