A High Flexible Shift Transformation Unit Design Approach for Coarse-Grained Reconfigurable Cryptographic Arrays

Abstract

Shift transformations are the fundamental operation of cryptographic algorithms, and the arithmetic unit implementing different types of shift transformations are utilized in the coarse-grain reconfigurable cryptographic architectures (CGRCA) to meet the different cryptographic algorithms. In this paper, a reconfigurable shift transformation unit (RSTU) is proposed to meet the complicated shift requirement of CGRCA, which achieves high flexibility and a good cost–performance ratio. The mathematical properties of shift transformation are analyzed, and several theorems are introduced to design a reconfigurable shifter. Furthermore, the reconfigurable data path of the proposed unit is presented to implement the random combination of shift operations in different granularity, and configuration word and routing algorithms are proposed to generate control information for RSTU. Moreover, the control information generation module is designed to invert the configuration word into the control information, according to the routing algorithms. As a proof-of-concept, the proposed RSTU is built using the CMOS 65 nm technology. The experimental results show that RSTU supports more shift operations, increases 18.2% speed at most, and reduces 13% area occupation, compared to the existing shifters.