Paper 2004/140

Architectures and Hardware Implementations of the 64-bit MISTY1 Block Cipher

P. Kitsos, M. D. Galanis, and O. Koufopavlou

Abstract

Two alternative architectures and VLSI implementations of the 64-bit NESSIE proposal, MISTY1 block cipher, are presented in this paper. For these implementations, FPGA devices were used. The first architecture is suitable for applications with high throughput requirements. A throughput of up to 7.2 Gbps can be achieved at a clock frequency of 96 MHz. The main characteristic of this implementation is that uses RAM blocks that are embedded in the FPGA device in order to implement the necessary by the algorithm S-boxes. The second architecture can be used in applications with constrained hardware resources. It uses feedback logic and inner pipeline with negative edge-triggered register. So, it causes the critical path to be shorter, without increasing the latency of the cipher execution. Compared with an implementation without inner pipeline, performance improvement of 97% is achieved. The measured throughput of the second architecture implementation is 561 Mbps at 79 MHz.