Digital content protection system

A digital content protection system that enables a digital content to be used and includes a recording medium apparatus having a storage area for holding digital content information and an access apparatus that reads information from and writes information into the storage area,

• the digital content protection system operating according to the following phases:
• an authentication phase where the recording medium apparatus secretly transmits an inherent key to the access apparatus, and the recording medium apparatus and the access apparatus perform mutual authentication using the inherent key, the inherent key being information that is unique to the recording medium apparatus;
• and
• a content transfer phase, performed only when the recording medium apparatus and the access apparatus have successfully authenticated each other, where the access apparatus either (a) encrypts a digital content using the secretly transmitted inherent key and sends the encrypted digital content to the recording medium apparatus or (b) receives an encrypted digital content from the recording medium apparatus and decrypts the encrypted digital content using the secretly transmitted inherent key,
• wherein the recording medium apparatus includes a first calculation means, and
• the access apparatus includes a first authentication information generating means and a first authentication means,
• wherein while the access apparatus judges whether the recording medium apparatus is legitimate in the authentication phase,
• the first authentication information generating means generates first authentication information and outputs the first authentication information to the recording medium apparatus,
• the first calculation means receives the first authentication information, generates first calculated authentication information by performing a first calculation on the received first authentication information using the inherent key, and outputs the first calculated authentication information to the access apparatus, and
• the first authentication means judges whether the recording medium apparatus is legitimate from the first authentication information and the first calculated authentication information using the secretly transmitted inherent key,
• wherein the access apparatus includes a second calculation means, and
• the recording medium apparatus includes a second authentication information generating means and a second authentication means,
• wherein while the recording medium apparatus judges whether the access apparatus is legitimate in the authentication phase,
• the second authentication information generating means generates second authentication information and outputs the second authentication information to the access medium apparatus,
• the second calculation means receives the second authentication information, generates second calculated authentication information by performing a second calculation on the received second authentication information using the secretly transmitted inherent key, and outputs the second calculated authentication information to the recording medium apparatus, and
• the second authentication means judges whether the access apparatus is legitimate from the second authentication information and the second calculated authentication information using the inherent key,
• wherein the recording medium apparatus further includes a first encryption means and an inherent key storing means for prestoring the inherent key, and
• the access apparatus further includes a first decryption means,
• wherein while the recording medium apparatus secretly transmits the inherent key to the access apparatus in the authentication phase,
• the first encryption means generates an encrypted inherent key by applying a first encryption algorithm to the inherent key and outputs the encrypted inherent key to the access apparatus, and
• the first decryption means receives the encrypted inherent key and generates a decrypted inherent key by applying a first decryption algorithm to the encrypted inherent key, the first decryption algorithm being used to decrypt cipher text generated with the first encryption algorithm,
• wherein the recording medium apparatus further includes a first key storing means for prestoring a first key, and
• the access apparatus further includes a second key storing means for prestoring a second key that corresponds to the first key,
• wherein the first encryption means encrypts the inherent key using the first key, and
• the first decryption means decrypts the encrypted inherent key using the second key,
• wherein the first key is a public key that is calculated from the second key according to a public key determination algorithm of a public key cryptosystem,
• the first encryption algorithm is an encryption algorithm of the public key cryptosystem, and
• the first decryption algorithm is a decryption algorithm of the public key cryptosystem,
• wherein the first encryption means encrypts the inherent key according to the encryption algorithm of the public key cryptosystem using the first key that is the public key, and
• the first decryption means decrypts the encrypted inherent key according to the decryption algorithm of the public key cryptosystem using the second key.

A digital content protection system that enables a digital content to be used and includes a recording medium apparatus having a storage area for holding digital content information and an access apparatus that reads information from and writes information into the storage area,

• the digital content protection system operating according to the following phases:
• an authentication phase where the recording medium apparatus secretly transmits an inherent key to the access apparatus, and the recording medium apparatus and the access apparatus perform mutual authentication using the inherent key, the inherent key being information that is unique to the recording medium apparatus;
• and
• a content transfer phase, performed only when the recording medium apparatus and the access apparatus have successfully authenticated each other, where the access apparatus either (a) encrypts a digital content using the secretly transmitted inherent key and sends the encrypted digital content to the recording medium apparatus or (b) receives an encrypted digital content from the recording medium apparatus and decrypts the encrypted digital content using the secretly transmitted inherent key,
• wherein the recording medium apparatus includes a first calculation means, and
• the access apparatus includes a first authentication information generating means and a first authentication means,
• wherein while the access apparatus judges whether the recording medium apparatus is legitimate in the authentication phase,
• the first authentication information generating means generates first authentication information and outputs the first authentication information to the recording medium apparatus,
• the first calculation means receives the first authentication information, generates first calculated authentication information by performing a first calculation on the received first authentication information using the inherent key, and outputs the first calculated authentication information to the access apparatus, and
• the first authentication means judges whether the recording medium apparatus is legitimate from the first authentication information and the first calculated authentication information using the secretly transmitted inherent key,
• wherein the access apparatus includes a second calculation means, and
• the recording medium apparatus includes a second authentication information generating means and a second authentication means,
• wherein while the recording medium apparatus judges whether the access apparatus is legitimate in the authentication phase,
• the second authentication information generating means generates second authentication information and outputs the second authentication information to the access medium apparatus,
• the second calculation means receives the second authentication information, generates second calculated authentication information by performing a second calculation on the received second authentication information using the secretly transmitted inherent key, and outputs the second calculated authentication information to the recording medium apparatus, and
• the second authentication means judges whether the access apparatus is legitimate from the second authentication information and the second calculated authentication information using the inherent key,
• wherein the recording medium apparatus further includes a first encryption means and an inherent key storing means for prestoring the inherent key, and
• the access apparatus further includes a first decryption means,
• wherein while the recording medium apparatus secretly transmits the inherent key to the access apparatus in the authentication phase,
• the first encryption means generates an encrypted inherent key by applying a first encryption algorithm to the inherent key and outputs the encrypted inherent key to the access apparatus, and
• the first decryption means receives the encrypted inherent key and generates a decrypted inherent key by applying a first decryption algorithm to the encrypted inherent key, the first decryption algorithm being used to decrypt cipher text generated with the first encryption algorithm,
• wherein the recording medium apparatus further includes a first key storing means for prestoring a first key, and
• the access apparatus further includes a second key storing means for prestoring a second key that corresponds to the first key,
• wherein the first encryption means encrypts the inherent key using the first key, and
• the first decryption means decrypts the encrypted inherent key using the second key,
• wherein the second key is a public key that is calculated from the first key according to a public key determination algorithm of a recovery signature processing method,
• the first encryption algorithm is a signature processing algorithm of the recovery signature processing method,
• the first encryption means generates the encrypted inherent key that is a signature text by applying the first encryption algorithm to the inherent key using the first key,
• the first decryption algorithm is a verification processing algorithm of the recovery signature processing method, and
• the first decryption means generates the decrypted inherent key by applying the first decryption algorithm to the encrypted inherent key that is the signature text using the second key.

A digital content protection system that enables a digital content to be used and includes a recording medium apparatus having a storage area for holding digital content information and an access apparatus that reads information from and writes information into the storage area,

• the digital content protection system operating according to the following phases:
• an authentication phase where the recording medium apparatus secretly transmits an inherent key to the access apparatus, and the recording medium apparatus and the access apparatus perform mutual authentication using the inherent key, the inherent key being information that is unique to the recording medium apparatus;
• and
• a content transfer phase, performed only when the recording medium apparatus and the access apparatus have successfully authenticated each other, where the access apparatus either (a) encrypts a digital content using the secretly transmitted inherent key and sends the encrypted digital content to the recording medium apparatus or (b) receives an encrypted digital content from the recording medium apparatus and decrypts the encrypted digital content using the secretly transmitted inherent key,
• wherein the recording medium apparatus includes a first calculation means, and
• the access apparatus includes a first authentication information generating means and a first authentication means,
• wherein while the access apparatus judges whether the recording medium apparatus is legitimate in the authentication phase,
• the first authentication information generating means generates first authentication information and outputs the first authentication information to the recording medium apparatus,
• the first calculation means receives the first authentication information, generates first calculated authentication information by performing a first calculation on the received first authentication information using the inherent key, and outputs the first calculated authentication information to the access apparatus, and
• the first authentication means judges whether the recording medium apparatus is legitimate from the first authentication information and the first calculated authentication information using the secretly transmitted inherent key,
• wherein the access apparatus includes a second calculation means, and
• the recording medium apparatus includes a second authentication information generating means and a second authentication means,
• wherein while the recording medium apparatus judges whether the access apparatus is legitimate in the authentication phase,
• the second authentication information generating means generates second authentication information and outputs the second authentication information to the access medium apparatus,
• the second calculation means receives the second authentication information, generates second calculated authentication information by performing a second calculation on the received second authentication information using the secretly transmitted inherent key, and outputs the second calculated authentication information to the recording medium apparatus, and
• the second authentication means judges whether the access apparatus is legitimate from the second authentication information and the second calculated authentication information using the inherent key,
• wherein the recording medium apparatus further includes a first encryption means and an inherent key storing means for prestoring the inherent key, and
• the access apparatus further includes a first decryption means,
• wherein while the recording medium apparatus secretly transmits the inherent key to the access apparatus in the authentication phase,
• the first encryption means generates an encrypted inherent key by applying a first encryption algorithm to the inherent key and outputs the encrypted inherent key to the access apparatus, and
• the first decryption means receives the encrypted inherent key and generates a decrypted inherent key by applying a first decryption algorithm to the encrypted inherent key, the first decryption algorithm being used to decrypt cipher text generated with the first encryption algorithm,
• wherein the recording medium apparatus further includes:
• a first master key storing means for prestoring a first master key group that includes a plurality of master keys;
• and
• a first selection means for selecting a master key out of the first master key group as a first key, and
• the access apparatus further includes:
• a second master key storing means for prestoring a second master key group that includes a plurality of master kegs, the first master key group and the second master key group include the same plurality of master keys;
• and
• a second selection means for selecting a master key out of the second master key group as a second key, the second key being the same as the first key,
• wherein the first encryption means encrypts the inherent key using the master key selected as the first key, and
• the first decryption means decrypts the encrypted inherent key using the master key selected as the second key.

A digital content protection system that enables a digital content to be used and includes a recording medium apparatus having a storage area for holding digital content information and an access apparatus that reads information from and writes information into the storage area,

• the digital content protection system operating according to the following phases:
• an authentication phase where the recording medium apparatus secretly transmits an inherent key to the access apparatus, and the recording medium apparatus and the access apparatus perform mutual authentication using the inherent key, the inherent key being information that is unique to the recording medium apparatus;
• and
• a content transfer phase, performed only when the recording medium apparatus and the access apparatus have successfully authenticated each other, where the access apparatus either (a) encrypts a digital content using the secretly transmitted inherent key and sends the encrypted digital content to the recording medium apparatus or (b) receives an encrypted digital content from the recording medium apparatus and decrypts the encrypted digital content using the secretly transmitted inherent key,
• wherein the recording medium apparatus includes a first calculation means, and
• the access apparatus includes a first authentication information generating means and a first authentication means,
• wherein while the access apparatus judges whether the recording medium apparatus is legitimate in the authentication phase,
• the first authentication information venerating means generates first authentication information and outputs the first authentication information to the recording medium apparatus,
• the first calculation means receives the first authentication information, generates first calculated authentication information by performing a first calculation on the received first authentication information using the inherent key, and outputs the first calculated authentication information to the access apparatus, and
• the first authentication means judges whether the recording medium apparatus is legitimate from the first authentication information and the first calculated authentication information using the secretly transmitted inherent key,
• wherein the access apparatus includes a second calculation means, and
• the recording medium apparatus includes a second authentication information generating means and a second authentication means,
• wherein while the recording medium apparatus judges whether the access apparatus is legitimate in the authentication phase,
• the second authentication information generating means generates second authentication information and outputs the second authentication information to the access medium apparatus,
• the second calculation means receives the second authentication information, generates second calculated authentication information by performing a second calculation on the received second authentication information using the secretly transmitted inherent key, and outputs the second calculated authentication information to the recording medium apparatus, and
• the second authentication means judges whether the access apparatus is legitimate from the second authentication information and the second calculated authentication information using the inherent key,
• wherein the recording medium apparatus further includes a first encryption means and an inherent key storing means for prestoring the inherent key, and
• the access apparatus further includes a first decryption means,
• wherein while the recording medium apparatus secretly transmits the inherent key to the access apparatus in the authentication phase,
• the first encryption means generates an encrypted inherent key by applying a first encryption algorithm to the inherent key and outputs the encrypted inherent key to the access apparatus, and
• the first decryption means receives the encrypted inherent key and generates a decrypted inherent key by applying a first decryption algorithm to the encrypted inherent key, the first decryption algorithm being used to decrypt cipher text generated with the first encryption algorithm,
• wherein the first encryption means prestores a first subgroup key, generates a transformed key by performing a first conversion on the inherent key using the first subgroup key, and generates the encrypted inherent key by applying the first encryption algorithm to the transformed key, and
• the first decryption means prestores a second subgroup key that is the same as the first subgroup key, generates a decrypted transformed key by applying the first decryption algorithm to the encrypted inherent key, and generates the decrypted inherent key by performing an inversion operation of the first conversion operation on the decrypted transformed key using the second subgroup key.

A digital content protection system that enables a digital content to be used and includes a recording medium apparatus having a storage area for holding digital content information and an access apparatus that reads information from and writes information into the storage area,

• the digital content protection system operating according to the following phases:
• an authentication phase where the recording medium apparatus secretly transmits an inherent key to the access apparatus, and the recording medium apparatus and the access apparatus perform mutual authentication using the inherent key, the inherent key being information that is unique to the recording medium apparatus;
• and
• a content transfer phase, performed only when the recording medium apparatus and the access apparatus have successfully authenticated each other, where the access apparatus either (a) encrypts a digital content using the secretly transmitted inherent key and sends the encrypted digital content to the recording medium apparatus or (b) receives an encrypted digital content from the recording medium apparatus and decrypts the encrypted digital content using the secretly transmitted inherent key,
• wherein the recording medium apparatus includes a first calculation means, and
• the access apparatus includes a first authentication information generating means and a first authentication means,
• wherein while the access apparatus judges whether the recording medium apparatus is legitimate in the authentication phase,
• the first authentication information generating means generates first authentication information and outputs the first authentication information to the recording medium apparatus,
• the first calculation means receives the first authentication information, generates first calculated authentication information by performing a first calculation on the received first authentication information using the inherent key, and outputs the first calculated authentication information to the access apparatus, and
• the first authentication means judges whether the recording medium apparatus is legitimate from the first authentication information and the first calculated authentication information using the secretly transmitted inherent key,
• wherein the access apparatus includes a second calculation means, and
• the recording medium apparatus includes a second authentication information generating means and a second authentication means,
• wherein while the recording medium apparatus judges whether the access apparatus is legitimate in the authentication phase,
• the second authentication information generating means generates second authentication information and outputs the second authentication information to the access medium apparatus,
• the second calculation means receives the second authentication information, generates second calculated authentication information by performing a second calculation on the received second authentication information using the secretly transmitted inherent key, and outputs the second calculated authentication information to the recording medium apparatus, and
• the second authentication means judges whether the access apparatus is legitimate from the second authentication information and the second calculated authentication information using the inherent key,
• wherein the first authentication means includes:
• a third calculation means for generating third calculated authentication information by performing a third calculation that is the same as the first calculation on the first authentication information using the secretly transmitted inherent key;
• and
• a first comparison means for judging whether the first calculated authentication information matches the third calculated authentication information and, if so, determining that the recording medium apparatus is legitimate.

A digital content protection system that enables a digital content to be used and includes a recording medium apparatus having a storage area for holding digital content information and an access apparatus that reads information from and writes information into the storage area,

• the digital content protection system operating according to the following phases:
• an authentication phase where the recording medium apparatus secretly transmits an inherent key to the access apparatus, and the recording medium apparatus and the access apparatus perform mutual authentication using the inherent key, the inherent key being information that is unique to the recording medium apparatus;
• and
• a content transfer phase, performed only when the recording medium apparatus and the access apparatus have successfully authenticated each other, where the access apparatus either (a) encrypts a digital content using the secretly transmitted inherent key and sends the encrypted digital content to the recording medium apparatus or (b) receives an encrypted digital content from the recording medium apparatus and decrypts the encrypted digital content using the secretly transmitted inherent key,
• wherein the recording medium apparatus includes a first calculation means, and
• the access apparatus includes a first authentication information generating means and a first authentication means,
• wherein while the access apparatus judges whether the recording medium apparatus is legitimate in the authentication phase,
• the first authentication information generating means generates first authentication information and outputs the first authentication information to the recording medium apparatus,
• the first calculation means receives the first authentication information, generates first calculated authentication information by performing a first calculation on the received first authentication information using the inherent key, and outputs the first calculated authentication information to the access apparatus, and
• the first authentication means judges whether the recording medium apparatus is legitimate from the first authentication information and the first calculated authentication information using the secretly transmitted inherent key,
• wherein the access apparatus includes a second calculation means, and
• the recording medium apparatus includes a second authentication information generating means and a second authentication means,
• wherein while the recording medium apparatus judges whether the access apparatus is legitimate in the authentication phase,
• the second authentication information generating means generates second authentication information and outputs the second authentication information to the access medium apparatus,
• the second calculation means receives the second authentication information, generates second calculated authentication information by performing a second calculation on the received second authentication information using the secretly transmitted inherent key, and outputs the second calculated authentication information to the recording medium apparatus, and
• the second authentication means judges whether the access apparatus is legitimate from the second authentication information and the second calculated authentication information using the inherent key,
• wherein the first calculation is a first encryption algorithm,
• the first calculation means generates the first calculated authentication information by applying the first encryption algorithm to the first authentication information using the inherent key, and
• the first authentication means generates first decrypted authentication information by applying a first decryption algorithm to the first calculated authentication information using the secretly transmitted inherent key, compares the first authentication information with the first decrypted authentication information, and judges, when the first authentication information matches the first decrypted authentication information, that the recording medium apparatus is legitimate,
• wherein the first decryption algorithm is used to decrypt a cipher text generated using the first encryption algorithm.

A The recording medium apparatus that has a storage area for holding digital content information and is used in a digital content protection system,

• wherein the digital content protection system enables a digital content to be used and further includes an access apparatus that reads information from and writes information into the storage area, and
• the digital content protection system operates according to the following phases:
• an authentication phase where the recording medium apparatus secretly transmits an inherent key to the access apparatus, and the recording medium apparatus and the access apparatus perform mutual authentication using the inherent key, the inherent key being information that is unique to the recording medium apparatus;
• and
• a content transfer phase, performed only when the recording medium apparatus and the access apparatus have successfully authenticated each other, where the access apparatus either (a) encrypts a digital content using the secretly transmitted inherent key and sends the encrypted digital content to the recording medium apparatus or (b) receives an encrypted digital content from the recording medium apparatus and decrypts the encrypted digital content using the secretly transmitted inherent key,
• wherein the recording medium apparatus includes a first calculation means, and
• the access apparatus includes a first authentication information generating means and a first authentication means,
• wherein while the access apparatus judges whether the recording medium apparatus is legitimate in the authentication phase,
• the first authentication information generating means generates first authentication information and outputs the first authentication information to the recording medium apparatus,
• the first calculation means receives the first authentication information, generates first calculated authentication information by performing a first calculation on the received first authentication information using the inherent key, and outputs the first calculated authentication information to the access apparatus, and
• the first authentication means judges whether the recording medium apparatus is legitimate from the first authentication information and the first calculated authentication information using the secretly transmitted inherent key,
• wherein the access apparatus includes a second calculation means, and
• the recording medium apparatus includes a second authentication information generating means and a second authentication means,
• wherein while the recording medium apparatus judges whether the access apparatus is legitimate in the authentication phase,
• the second authentication information generating means generates second authentication information and outputs the second authentication information to the access medium apparatus,
• the second calculation means receives the second authentication information, generates second calculated authentication information by performing a second calculation on the received second authentication information using the secretly transmitted inherent key, and outputs the second calculated authentication information to the recording medium apparatus, and
• the second authentication means judges whether the access apparatus is legitimate from the second authentication information and the second calculated authentication information using the inherent key,
• wherein the first authentication means includes:
• a third calculation means for generating third calculated authentication information by performing a third calculation that is the same as the first calculation on the first authentication information using the secretly transmitted inherent key;
• and
• a first comparison means for judging whether the first calculated authentication information matches the third calculated authentication information and, if so, determining that the recording medium apparatus is legitimate.

An access apparatus that reads information from and writes information into a storage area of a recording medium apparatus and is included in a digital content protection system,

• wherein the storage area holds digital content information,
• the digital content protection system enables a digital content to be used and includes the recording medium apparatus and the access apparatus,
• wherein the digital content protection system operates according to the following phases:
• an authentication phase where the recording medium apparatus secretly transmits an inherent key to the access apparatus, and the recording medium apparatus and the access apparatus perform mutual authentication using the inherent key, the inherent key being information that is unique to the recording medium apparatus;
• and
• a content transfer phase, performed only when the recording medium apparatus and the access apparatus have successfully authenticated each other, where the access apparatus either (a) encrypts a digital content using the secretly transmitted inherent key and sends the encrypted digital content to the recording medium apparatus or (b) receives an encrypted digital content from the recording medium apparatus and decrypts the encrypted digital content using the secretly transmitted inherent key,
• wherein the recording medium apparatus includes a first calculation means, and
• the access apparatus includes a first authentication information generating means and a first authentication means,
• wherein while the access apparatus judges whether the recording medium apparatus is legitimate in the authentication phase,
• the first authentication information generating means generates first authentication information and outputs the first authentication information to the recording medium apparatus,
• the first calculation means receives the first authentication information, generates first calculated authentication information by performing a first calculation on the received first authentication information using the inherent key, and outputs the first calculated authentication information to the access apparatus, and
• the first authentication means judges whether the recordings medium apparatus is legitimate from the first authentication information and the first calculated authentication information using the secretly transmitted inherent key,
• wherein the access apparatus includes a second calculation means, and
• the recording medium apparatus includes a second authentication information generating means and a second authentication means,
• wherein while the recording medium apparatus judges whether the access apparatus is legitimate in the authentication phase,
• the second authentication information generating means generates second authentication information and outputs the second authentication information to the access medium apparatus,
• the second calculation means receives the second authentication information, generates second calculated authentication information by performing a second calculation on the received second authentication information using the secretly transmitted inherent key, and outputs the second calculated authentication information to the recording medium apparatus, and the second authentication means judges whether the access apparatus is legitimate
• from the second authentication information and the second calculated authentication information using the inherent key,
• wherein the first authentication means includes:
• a third calculation means for generating third calculated authentication information by performing a third calculation that is the same as the first calculation on the first authentication information using the secretly transmitted inherent key;
• and
• a first comparison means for judging whether the first calculated authentication information matches the third calculated authentication information and, if so, determining that the recording medium apparatus is legitimate.