AUTHENTICATION METHOD, ENCRYPTION METHOD, DECRYPTION METHOD, CRYPTOGRAPHIC SYSTEM AND RECORDING MEDIUM

摘要

An authentic method, encryption method, decryption method, cryptographic system and recording medium are disclosed. The present invention includes the steps of decrypting authentication information (301 ) and a content provider's public key (302) stored in a certificate (305) signed by a certificate authority to authenticate the content provider using the decrypted authentication information (301) and authenticating the public key (302) of the content provider by checking the decrypted public key of the content provider. And, the present invention provides the encryption method includes the steps of encrypting content data (1002) with a secret key (1004), encrypting the secret key (1004) with a public key (100/), and transferring the encrypted content data (1005) and the encrypted secret key (1008).