  With the proliferation of high-speed wireless networking, the necessity for
efficient, robust and secure encryption modes is ever increasing. But,
cryptography is primarily a computationally intensive process. This paper
investigates the performance and efficiency of IEEE 802.11i approved Advanced
Encryption Standard (AES)-Rijndael ciphering/deciphering software in Cipher
Block Chaining (CBC) mode. Simulations are used to analyse the speed, resource
consumption and robustness of AES-CBC to investigate its viability for image
encryption usage on common low power devices. The detailed results presented in
this paper provide a basis for performance estimation of AES cryptosystems
implemented on wireless devices. The use of optimized AES-CBC software
implementation gives a superior encryption speed performance by 12 - 30%, but
at the cost of twice more memory for code size.
