FIELD: information technology.
SUBSTANCE: configuration is provided wherein usage restrictions of an application are determined in accordance with timestamps. A certificate revocation list (CRL) in which the revocation information of a content owner who is a provider of an application recorded on a disc is recorded is referred to verify whether or not a content owner identifier recorded in an application certificate is included in the CRL, and in the case that the content owner identifier is included in the CRL, comparison between a timestamp stored in a content certificate and a CRL timestamp is executed, and in the case that the content certificate timestamp has date data coinciding with or later than the CRL timestamp, utilisation processing of the application program is prohibited or restricted. A configuration is realised wherein an unrevoked application is not subjected to utilisation restriction, and only a revoked application is subjected to utilisation restriction.
EFFECT: high protection of content from unauthorised reading and usage.
20 cl, 9 dwg
