Embedded Systems: Hardware, Design and Implementation

13

Advanced Encryption Standard (AES) Implementation in Embedded Systems

ISSAM HAMMAD, KAMAL EL-SANKARY, and EZZ EL-MASRY

13.1 INTRODUCTION

The word “cryptography” refers to the change of data representation from its original form into another different form in order to make it hidden and secured. Cryptography has two processes; the first process is the encryption, where the original data are converted into secured form using certain steps. The second process is the decryption, where the encrypted data are restored to the original form by applying the inverse to the steps applied in the encryption process. Classical cryptography started thousands of years ago. Historically, classical cryptography was used for secret communications between people. This kind of cryptography is usually applied by substituting the message letters by other letters using certain formula, for example substituting each letter in a message with the next letter in the alphabets so that the word “Test” would become “Uftu.”

In modern ages, cryptography development has been a major concern in the fields of mathematics, computer science, and engineering. One of the main classes in cryptography today is the symmetric-key cryptography, where a shared key of a certain size will be used for the encryption and decryption processes.

Nowadays, cryptography has a main role in embedded systems design. As the number of devices and applications which send and receive data are increasing rapidly, the data transfer rates ...