Communication system, communication apparatus, communication method, and computer program

摘要

Content is transmitted within a range of the user's legitimate use while limiting the number of equipment to which the content is transmitted at the same time.;A content using apparatus periodically transmits an exchange key and the corresponding key ID using a command. Only while receiving the key ID at predetermined reception cycles, a content providing apparatus maintains the corresponding exchange key. When not periodically receiving the key ID, the content providing apparatus destroys the corresponding exchange key. After that, when receiving a command including the key ID, the content providing apparatus returns a response including information indicating that the exchange key has become invalid.

主权项

1. A communication apparatus, comprising:
circuitry configured to:
register a sink apparatus with a first piece of identification information associated with the sink apparatus;receive a key and a challenge signal in a challenge and response procedure;store the key according to a result of a comparison between the first piece of identification information and a second piece of identification information that is transmitted with the challenge signal;start a timer to maintain the key;erase the key according to a time value, counted by the timer, compared to a predetermined time value;maintain a number count representing a number of registered sink apparatuses;increase the number count when a new sink apparatus is registered; andstop registering new sink apparatuses according to a number value, of the number count, compared to a predetermined number value.