Patent ID: 7844831

Claim:
A smart card comprising: a bidirectional I/O terminal for transmitting data to and receiving data from an external card reader host; a data storage unit to control access to data received at and transmitted from the I/O terminal with a stream-encrypted bidirectional authentication, the data storage unit storing a number of read access passwords and a number of write passwords and providing stream encryption to encrypt said read access passwords and write access passwords and to certify authentication of a transaction between the smart card and the external card reader host using a dual authentication protocol; and a stream-encrypted hash unit to receive an initiation vector defined by the smart card issuer and stored in the smart card associated with a secret key, compute a first value for authenticating the external card reader host with an incoming first challenge, compute a second value for authenticating the smart card with an outgoing second challenge, and compute a third value for use as a data encryption key, wherein the hash unit is to receive stream-encrypted read access passwords and verify the stream-encrypted read access passwords and send stream-encrypted data to the external host card reader, and wherein the hash unit is to receive stream-encrypted write access passwords and verify the stream-encrypted write access passwords and accept stream-encrypted data, and wherein the data storage unit and stream-encrypted hash unit are free of a microprocessor.