Preboot protection for a data security system with anti-intrusion

Abstract

A secure computer controlling access to data storage devices via a card reader. A microprocessor-controlled card reader interface logically connected to the card reader and the central processing unit (CPU) of the computer reads and writes information from and to a card placed in the card reader and performs additional functions in response to commands received from the CPU. The card reader interface includes an encryption engine for encrypting data in a data storage device and a boot ROM containing verification program code executed during an initialization procedure. The verification program verifies that a valid user card has been placed in the card reader, reads one or more questions from the user card, asks the questions of the user and verifies the answers against the contents of the card. If authorization is verified, the card reader interface permits the user to access the encrypted data. Otherwise the user is denied access to the data by one or more of the following methods: freezing the system bus, and requiring the user to reset the computer and re-enter the verification program; logically destroying the data in the data storage devices; and physically destroying the data storage devices.