This chapter introduces several hardware implementations that can be often used for block ciphers, focusing on AES. AES is widespread and plays a significant role to guarantee the security of many secure systems. The AES hardware can be implemented on a wide variety of architectures with synchronous-style design. There exist several options depending on the requirement for speed performance, area cost, and so on. General discussions on hardware architecture are firstly mentioned, and secondly the AES hardware implementations are introduced. Finally, we explore the details of the merits and demerits of each architecture throughout this chapter.
3.1 Parallel Architecture
In order to achieve a high-throughput performance, a hardware implementation is designed to process several operations or modules simultaneously. It is called parallel architecture and often used in timing-critical and real-time systems. It can also be understood that designers aiming at such parallelism have to increase the value of discussed in Section 2.6.2.
3.1.1 Comparison between Serial and Parallel Architectures
Power consumption of the parallel architecture is relatively large as signal toggles are increased in proportion to the number of parallelized modules. For instance, Figure 3.1 shows an example, where four independent 8-bit additions are implemented ...