Embedded Systems: Hardware, Design and Implementation

14

Reconfigurable Architecture for Cryptography over Binary Finite Fields

SAMUEL ANTÃO, RICARDO CHAVES, and LEONEL SOUSA

14.1 INTRODUCTION

Security is becoming mandatory for embedded systems in a wide range of fields and applications. Not only fast, but scalable and flexible implementations of cryptographic procedures are also demanded in these systems. Elliptic curve (EC) cryptography and the Advanced Encryption Standard (AES) are two of the main building blocks of the currently used cryptographic procedures on embedded systems, enabling support for public-key and private-key protocols. This chapter starts by introducing the mathematical details underlying the addressed applications, highlighting possible directions for efficient implementations of the arithmetic units. Following this introduction, the developed approach to exploit the programmability of a microcoded processor, the efficiency of hardwired finite-field arithmetic units, and the flexibility of the run-time hardware reconfiguration in an architecture targeting both EC and AES is discussed. Furthermore, the development of other cryptographic relevant functionalities, such as random number generators (RNGs), is also addressed. A fully functional prototype supported by a field-programmable gate array (FPGA) technology is designed and tested, tending an in-depth analysis of the adopted approach.

This chapter is organized as follows. Section 14.2 presents the EC and the AES properties, including different arithmetic approaches ...