In the 21st century, where Internet plays a major role in everyone's day-to-day life, security of information has become a major concern. Due to the advancement in technology, it has become even more challenging to protect the data from the intruders. "Cryptography" derived from Greek word kryptos meaning "Hidden", is an art of protecting information by transforming it into an unreadable format. Symmetric key cryptography also called secret key cryptography is a simpler and faster means of data transfer through an unreliable channel. It requires fewer overheads in terms of speed and energy cost than public key cryptosystem.