A Low Cost Implementation of Modified Advanced Encryption Standard Algorithm Using 8085a Microprocessor

The high security communication systems became an urgent need in recent years for both governments and peoples desiring protection from signal interception. Advanced Encryption Standard (AES) is a famous block encryption algorithm which has several advantages in data encryption. However, AES suffer from some drawbacks such as high computations, pattern appearance if apply for image encryption, and more hardware requirements. These problems are more complicated when the AES algorithm is used for multimedia encryption. New modification to AES-128 algorithm which reduce the computations and hardware requirements are proposed by enforcement Mixcolumn transformation in five rounds instead of nine rounds as in original AES-128. Second proposed is suggest new simple S-box used for encryption and decryption. The implementation of advanced encryption standard algorithm is important requirement where many researches proposed different items to this purpose. A simply item proposed in this paper to speedy, low cost implementation of Modified Advanced Encryption Standard (MAES) cryptographic algorithm is 8085A microprocessor. The results prove that the modifications of AES make implementation it by 8085A microprocessor more effective.