Information processing device, information storage device, server, information processing system, information processing method and medium for reproduction of encrypted content

An information processing device, comprising:

• one or more hardware processors configured to:
• store, in a medium, an encrypted content that is encrypted based on a title key and execute decryption processing of the encrypted content;
• acquire, from the medium, a converted title key obtained based on conversion of the title key which is an encryption key applied to the decryption of the encrypted content, and a user token obtained based on conversion of binding secret information applied to calculate the title key from the converted title key,
• wherein the user token is generated based on user identification information associated with a user, and wherein the user identification information corresponds to a User ID and a password included in registration account information associated with the user;
• generate an authentication key based on of the user identification information and an application key stored in the information processing device, wherein the authentication key is generated by encryption of the User ID based on a hash value of the password included in the registration account information, and the application key;
• calculate the binding secret information by computation processing between the user token and the authentication key;
• calculate the title key from the converted title key by application of the calculated binding secret information;
• execute the decryption processing of the encrypted content by application of the calculated title key,
• execute decryption processing of the user token to which the authentication key is applied, to calculate the binding secret information and a verification value for the binding secret information;
• and
• execute verification processing of the calculated binding secret information based on the calculated verification value.

A server configured to transmit an encrypted content to an information storage device, the server comprising:

• one or more hardware processors configured to:
• receive user identification information associated with a user from an information processing device equipped with the information storage device;
• generate a user token by computation processing to which the received user identification information is applied, and a converted title key which is converted data of a title key applied to encryption processing of the encrypted content,
• wherein the user token is generated by encryption of binding secret information based on an authentication key, wherein the authentication key is generated by encryption of a User ID based on a hash value of a password associated with the User ID, and an application key stored in the information processing device, and wherein the User ID and the password are included in registration account information of the user;
• and
• transmit the generated user token and converted title key as stored data of the information storage device,
• wherein the user ID and the password as the user identification information are received as the user identification information, and the authentication key is generated by computation processing with respect to the user ID, the password, and the application key, and
• wherein binding secret information is generated as an inherent value that corresponds to the encrypted content, and the user token is generated by encryption processing to which the authentication key for the binding secret information is applied.

A non-transitory computer-readable medium having stored thereon, computer-executable instructions causing a computer which controls an information storage device comprising one or more hardware processors to perform operations, the operations comprising:

• storing an encrypted content, a converted title key obtained based on conversion of a title key which is a decryption key of the encrypted content, and a user token obtained based on conversion of binding secret information applied to calculate the title key from the converted title key, wherein the user token is generated based on user identification information associated with a user, and wherein the user identification information corresponds to a User ID and a password included in registration account information associated with the user;
• reproducing the encrypted content;
• acquiring the converted title key and the user token from the information storage device;
• generating an authentication key based on the user identification information that is acquired by input processing through an input unit or read-out processing from a memory;
• wherein the authentication key is generated by encryption of the User ID based on a hash value of the password included in the registration account information and an application key stored in the information processing device;
• calculating the binding secret information by computation processing between the user token and the authentication key;
• calculating the title key from the converted title key by application of the calculated binding secret information;
• and
• executing decryption processing of the encrypted content by application of the calculated title key.

An information processing method, comprising:

• in an information storage device comprising one or more hardware processors:
• storing an encrypted content, a converted title key obtained by converting a title key which is an encryption key applied to decryption of the encrypted content, and a user token obtained by converting binding secret information applied to calculate the title key from the converted title key,
• wherein the user token is generated by encryption of the binding secret information based on an authentication key, and wherein the authentication key is generated by encryption of a User ID based on a hash value of a password associated with the User ID, and an application key stored in an external device that reproduces the encrypted content, and wherein the User ID and the password are included in registration account information of a user;
• and
• controlling access of the external device to the information storage device, wherein the external device having an access right is confirmed therein to read out the user token,
• wherein the user token is data encrypted based on the authentication key with respect to data that includes the binding secret information and a verification value for the binding secret information, and
• wherein the binding secret information is a value inherent in the encrypted content.

An information processing method, comprising:

• in an information processing device that decrypts and reproduces content stored in a medium, the information processing device comprising one or more hardware processors:
• storing, in the medium, an encrypted content that is encrypted using a title key and executing decryption processing of the encrypted content;
• acquiring, from the medium, a converted title key obtained by converting the title key which is an encryption key applied to the decryption of the encrypted content, and a user token obtained by converting binding secret information applied to calculate the title key from the converted title key, wherein the user token is generated based on user identification information associated with a user, and wherein the user identification information corresponds to a User ID and a password included in registration account information associated with the user;
• generating an authentication key based on the user identification information and an application key stored in the information processing device, wherein the authentication key is generated by encryption of the User ID based on a hash value of the password included in the registration account information and the application key;
• calculating the binding secret information by computation processing between the user token and the authentication key;
• calculating the title key from the converted title key by applying the calculated binding secret information;
• executing the decryption processing of the encrypted content by applying the calculated title key,
• executing decryption processing of the user token to calculate the binding secret information and a verification value, and
• executing verification processing of the calculated binding secret information based on the calculated verification value.

An information processing method, comprising:

• in a server that transmits content to an information storage device, the server comprising one or more hardware processors:
• receiving user identification information associated with a user from an information processing device equipped with the information storage device;
• generating a user token by computation processing to which the received user identification information is applied, and a converted title key which is converted data of a title key applied to encryption processing of the encrypted content,
• wherein the user token is generated by encryption of binding secret information based on an authentication key, and wherein the authentication key is generated by encryption of a User ID based on a hash value of a password associated with the User ID, and an application key stored in the information processing device, and wherein the User ID and the password are included in registration account information of a user;
• transmitting the generated user token and converted title key as stored data of the information storage device,
• wherein the user ID and the password as the user identification information are received as the user identification information, and the authentication key is generated by computation processing with respect to the user ID, the password, and the application key, and
• wherein binding secret information is generated as an inherent value that corresponds to the encrypted content, and the user token is generated by encryption processing to which the authentication key for the binding secret information is applied.

A non-transitory computer-readable medium having stored thereon, computer-executable instructions causing a computer which controls an information storage device comprising one or more hardware processors to perform operations, the operations comprising:

• storing an encrypted content, a converted title key obtained by converting a title key which is an encryption key applied to decryption of the encrypted content, and a user token obtained by converting binding secret information applied to calculate the title key from the converted title key,
• wherein the user token is generated by encryption of the binding secret information based on an authentication key, and wherein the authentication key is generated by encryption of a User ID based on a hash value of a password associated with the User ID, and an application key stored in an external device that reproduces the encrypted content, and wherein the User ID and the password are included in registration account information of a user;
• and
• controlling access of the external device to the information storage device, wherein the external device having an access right is confirmed therein to read out the user token,
• wherein the user token is data encrypted based on the authentication key with respect to data that includes the binding secret information and a verification value for the binding secret information, and
• wherein the binding secret information is a value inherent in the encrypted content.

A non-transitory computer-readable medium having stored thereon, computer-executable instructions causing a computer which controls an information processing device comprising one or more hardware processors to perform operations, the operations comprising:

• storing, in a medium, an encrypted content that is encrypted using a title key and executing decryption processing of the encrypted content;
• acquiring, from the medium, a converted title key obtained by converting the title key which is an encryption key applied to the decryption of the encrypted content, and a user token obtained by converting binding secret information applied to calculate the title key from the converted title key,
• wherein the user token is generated based on user identification information associated with a user, and wherein the user identification information corresponds to a User ID and a password included in registration account information associated with the user;
• generating an authentication key based on the user identification information and an application key stored in the information processing device that reproduces the encrypted content, wherein the authentication key is generated by encryption of the User ID based on a hash value of the password included in the registration account information and the application key;
• calculating the binding secret information by computation processing between the user token and the authentication key;
• calculating the title key from the converted title key by applying the calculated binding secret information;
• and
• decrypting processing of the encrypted content by applying the calculated title key,
• executing decryption processing of the user token to calculate the binding secret information and a verification value, and
• executing verification processing of the calculated binding secret information based on the calculated verification value.