Patent ID: 9172531
Filing Date: 2015-10-27
Classification: H04H,H04L

Abstract:
1. A communication device that receives encrypted content, the communication device comprising: circuitry configured to transmit a certificate pertaining to the communication device for reception by another communication device, receive a random value transmitted by the another communication device, to generate a response including information based on the received random value and on a secret key stored in the communication device, to transmit the response to the another communication device, and to receive key information from the another communication device, the certificate having identification (ID) information pertaining to the communication device, when (i) the (ID) information of the communication device is determined not to be already registered in a registration list of the another communication device and (ii) a count of communication devices that receive the key information is determined to be equal to or greater than a predefined maximum value, a first authentication which is performed is considered to have failed wherein the random value is not received by the communication device, and when the performed first authentication is considered to have not failed the random value is received by the communication device and the response is generated and transmitted for reception by the another communication device, and after the first authentication is performed and determined to have not failed, a second authentication is performed which is considered to have failed if the information in the response is mismatched with information held in the another communication device during a judging operation performed by the another communication device with use of a key which is different from the secret key stored in the communication device wherein the key information from the another communication device is not received.