Patent ID: 7287282
Filing Date: 2007-10-23
Classification: G06F,H04L

Abstract:
1. A copyright protection system for controlling a distribution of data according to a predetermined number of permitted distributions of the data, the data requiring copyright protection, the copyright protection system comprising: at least one reception unit connected to a network and that transmits a request to receive the data, the at least one reception unit including an authentication receptor for transmitting an authentication request for carrying out an authentication; and a transmission unit for receiving the request to receive the data and for transmitting the data via the network to be used by the at least one reception unit based on the number of permitted distributions and a successful authentication between the transmission unit and the at least one reception unit, the transmission unit including an authentication processor for receiving the authentication request and for carrying out the authentication with the at least one reception unit, and an authentication number counter for counting and storing a number of successful authentications, wherein the transmission unit determines that the authentication is successful if the stored number of successful authentications is less than the predetermined number of distributions, and the authentication number counter decrements the stored number of successful authentications after determining that the at least one reception unit no longer uses the data; wherein the authentication number counter increments the stored number of successful authentications after determining that the authentication processor successfully carries out the authentication; wherein the copyright protection system further comprises a bridge unit connecting the network to another network; wherein the bridge unit is handled in a same manner as the transmission unit in the other network; if the authentication request is carried out by the at least one reception unit connected to the other network, authentication is carried out for the transmission unit connected to the network before authentication is carried out for the at least one reception unit and, if the authentication for the transmission unit is successful, authentication is carried out for the at least one reception unit; and wherein the bridge unit has a key counter for counting a limitation number of a permissions allocated by the transmission unit that is connected to the network, the authentication number counter of the bridge unit counts the number of successful authentications carried out for the at least one reception unit, which is connected to the other network, by the authentication processor on a transmission side of the bridge unit, the bridge unit sets the number of successful authentications carried out for the transmission unit, which is connected to the network, as the limitation number of the permissions counted by the key counter, in a case that a decrement authentication request is carried out, in order to decrement the number counted by the authentication number counter of the bridge unit, by the at least one reception unit that is connected to the other network, the bridge unit does not carry out decrement authentication for the transmission unit that is connected to the network but, rather, carries out decrement authentication for the at least one reception unit, the authentication number counting means of the bridge unit decrements the number of successful authentications when the decrement authentication is successful, and at a time when the authentication request is newly carried out by the at least one reception unit connected to the other network, authentication is carried out for the at least one reception unit if the limitation number of the permissions is smaller than the number of successful authentications that is counted by the authentication number counter of the bridge unit while authentication is carried out for the transmission unit connected to the network before authentication is carried out for the at least one reception unit if the limitation number of the permissions is not smaller than the number of successful authentications counted by the authentication number counter of the bridge unit and, then, authentication is carried out for the at least one reception unit if the authentication for the transmission unit is successful.