Verfahren und System zum Schutz digitaler Informationen

摘要

A digital information protection scheme using an improved security protocol. In a system in which a user makes an access to a digital information provided by an information center (1) by connecting a computer card (3) owned by the user to an information terminal device (2) connected with the information center (1), a work key for encrypting a desired digital information is delivered from the information center (1) to the computer card (3) through the information terminal device (2), and the work key is registered in the computer card (3); the desired digital information encrypted by the work key is delivered from the information center (1) to the information terminal device (2); and an encrypted digital information delivered from the information center (1) is decrypted at the information terminal device (2) by using the work key registered in the computer card (3), and a decrypted digital information is provided to the user at the information terminal device (2).