An integrated circuit card (ICC), more popularly known as a smart card, temperresistant, computer programmable data storage. It has the exact shape and size of a debit(ATM) card, but can hold 4KB-64KB of information and perform modest amount of data processing as well. Smart card ensures data security and integrity. By data security we mean that the data value or computation contained on the card can be accessed by the authorised person or department. Data integrity guarantees that the value of the data stored on the card is defined at all the times and is not corrupted. This property must hold even if power to the smart card is cut during the computation involving the information on the card.