A Novel Combinatorics-Based Reconfigurable Bit Permutation Network and Its Circuit Implementation

• Published in: Chinese Journal of Electronics Vol. 24; no. 3; pp. 513 - 523
• Main Authors: Shan, Weiwei, Chen, Xin, Lu, Yinchao, Li, Jie
• Format: Journal Article
• Language: English
• Published: Published by the IET on behalf of the CIE 01.07.2015
• Subjects: BENES; Bit; circuit; circuits; CMOS digital integrated circuits; CMOS process; combinatorics theory; complementary metal oxide semiconductor; coprocessors; Cryptographic; cryptographic algorithm; cryptography; Digital; elementary seed network; integrated; multiplexor; network routing; OMFLIP network; permutation; Reconfigurable; reconfigurable bit permutation network; reconfigurable cipher coprocessor; recursive subnetwork; routing algorithm; size 0.18 mum; recursive subnetwork; elementary seed network; network routing; cryptography; CMOS process; coprocessors; CMOS digital integrated circuits; multiplexor; complementary metal oxide semiconductor; reconfigurable bit permutation network; OMFLIP network; routing algorithm; combinatorics theory; reconfigurable cipher coprocessor; BENES; cryptographic algorithm; size 0.18 mum
• ISSN: 1022-4653; 2075-5597
• DOI: 10.1049/cje.2015.07.013

Bit permutation is an important operation in many applications. A novel reconfigurable N × N bit permutation network with a compact structure is presented. It is based on combinatorics theory by cascading two recursive N/2 × N/2 sub-networks, while each subnetwork is cascaded by two N/4 × N/4 sub-networks, and so on cascaded until reaching the elementary 4 × 4 seed networks. Its routing algorithm is also established to determine each multiplexor’s status. Then the circuits of different sized permutation networks in a reconfigurable cipher co-processor were designed and implemented in 0.18μm CMOS process. The proposed circuit can achieve an arbitrary n × n permutation and support all types of bit permutations in many cryptographic algorithms. Plus, it consumes less multiplexors than commonly used BENES and OMFLIP networks.