Patent ID: 7065648
Filing Date: 2006-06-20
Classification: G06Q,G11B

Abstract:
1. A mutual authentication method for use between a recording apparatus which records copied contents in a memory card as a removable recording medium having an arithmetic processing function, and the memory card, said method comprising: storing, in a first read-only semiconductor memory in the memory card, first information which depends on the memory card; storing, in a second semiconductor memory in the memory card, secret information obtained by encrypting the first information using second information which is to be shared by the memory card in executing mutual authentication with the recording apparatus and which depends on the memory card, the second semiconductor memory having a public area accessible by an access procedure and a secret area accessible only by a private access procedure, the secret information being stored in the secret area; generating, by the recording apparatus, authentication information used in mutual authentication with the memory card on the basis of the first information obtained from the memory card; executing mutual authentication between the recording apparatus and the memory card using the generated authentication information and the secret information, wherein executing the mutual authentication includes storing, by the memory card, the first key in the secret area of the memory card; encrypting, by the recording apparatus, a content key using the second key and transferring the encrypted content key to the memory card; encrypting, by the recording apparatus, a content using the content key and transferring the encrypted content to the memory card; and storing, by the memory card, the encrypted content key and the encrypted content in the public area of the memory card.