Modern cryptographic protocols like TLS, SSL, etc. provide communication security by employing symmetric or secret key algorithms for encrypting the data and asymmetric or public key algorithms for key exchange. Modern microprocessors are loaded with a lot of performance optimization features. Single Instruction Multiple Data (SIMD) instruction set feature specially designed for improving the performance of multimedia applications is one among them. But most of the encryption algorithms do not use these features to its fullest. This paper discusses various optimization principles to be followed by encryption algorithm designers to exploit the features of underlying processor to the maximum.