Patent ID: 7539306
Filing Date: 2009-05-26
Classification: G06F,G11B,H04N

Abstract:
1. A key delivery apparatus that manages a decryption key for decrypting an encrypted content and manages a suppliable number, which is a number indicating a number of times the decryption key can be supplied to a terminal apparatus connected to the key delivery apparatus via a network, the key delivery apparatus comprising: a receiving unit configured to receive, from the terminal apparatus, a supply request, which is a request for the decryption key; a supply determining unit configured to determine whether the terminal apparatus is a terminal apparatus of a first-type that manages a content-usage period, and whether the terminal apparatus is a terminal apparatus of a second-type that does not manage the content-usage period; and a key supply unit configured, when the suppliable number indicates that the decryption key can be supplied, to supply, to the terminal apparatus, (i) the decryption key and a key-usage period, which imposes a restriction on usage of content and is related to the decryption key, when the supply determining unit determines that the terminal apparatus is of the first-type, and (ii) the decryption key, without the key-usage period such that a restriction on usage of content is not imposed on the terminal apparatus, when the supply determining unit determines that the terminal apparatus is of the second-type, wherein the supply request includes one of first information and second information, the first information indicating that the encrypted content is stored in the terminal apparatus, and the second information indicating that the encrypted content is stored on a portable recording medium inserted into the terminal apparatus, the supply determining unit determines, based on the received supply request, whether the terminal apparatus records the encrypted content on the portable recording medium, and the supply determining unit determines that the terminal apparatus is of the first-type when the supply determining unit determines that the terminal apparatus records the encrypted content onto the portable recording medium.