Efficient Modular-Pipelined AES Implementation in Counter Mode on ALTERA FPGA

Abstract

This paper describes a high performance single-chip FPGA implementation of the new Advanced Encryption Standard (AES) algorithm dealing with 128-bit data/key blocks and operating in Counter (CTR) mode. Counter mode has a proven-tight security and it enables the simultaneous processing of multiple blocks without losing the feedback mode advantages. It also gives the advantage of allowing the use of similar hardware for both encryption and decryption parts. The proposed architecture is modular. The architecture basic module implements a single round of the algorithm with the required expansion hardware and control signals. It gives very high flexibility in choosing the degree of pipelining according to the throughput requirements and hardware limitations and this gives the ability to achieve the best compromised design due to these aspects. The FPGA implementation presented is that of a pipelined single chip Rijndael design which runs at a rate of 10.8 Gbits/sec for full pipelining on an ALTERA APEX-EP20KE platform.