Supplemental cryptographic hardware for smart cards

A smart card is a small computer in credit card format with no man-machine interface. This industry wide recognition expresses an essential fact. The specific properties of smart cards, compared with all other types of cards, are determined by a microcontroller integrated in a card, which controls, initiates, and monitors all activities. Software alone cannot satisfy all smart card requirements. Manufacturers must offer additional functions in hardware. The authors describe true random-number generators and an advanced encryption standard computation unit: two different special-purpose hardware blocks that can be integrated on the silicon substrate along with the usual functional units of a smart card microcontroller.