Patent attributes
An electronic data flash card includes a random number generator that generates a random number stored in the card and a host system each time the card is accessed by the host system. The random number is used by the host system to encrypt a logical branch address, a user password, and user data that is written to and stored in a secure area of the card. The random number is encrypted using a key associated with the card, and the encrypted random number is stored by the card with the associated encrypted data. The random number is not stored in the host system. A new random number is generated each time the card is queried. In a read process the host system decrypts the encrypted random number using the key, then uses the random number to decrypt the associated encrypted data. Access to read/write processes are password protected.
