Patent ID: 7657742

Claim:
A content reproducing apparatus which executes multiple authentication processes with a recording medium by use of certificate data and reproduces, when succeeding in said authentication processes, a content of said recording medium, said multiple authentication processes including a current authentication process and a subsequent authentication process which occurs subsequent to said current authentication process, comprising: a first non-volatile memory for storing one identification number indicating certificate data that is used in said current authentication process; a second non-volatile memory for storing a plurality of certificate data in an ascending order according to an identification number identifying each certificate data; an authenticator for executing said current authentication process with said recording medium by use of the certificate data retrieved from said second non-volatile memory according to the identification number stored in said first non-volatile memory; and a renewer for renewing, when failing in said current authentication process, the identification number stored in said first non-volatile memory to an identification number that indicates next unused certificate data in the ascending order, which has not been used prior to said current authentication process, such that use of said next unused certificate data results in a succeeding in said current authentication process, the authenticator using first in said subsequent authentication process the identification number indicating certificate data that results in the succeeding in said current authentication process, the authenticator not using in said subsequent authentication process an identification number indicating certificate data that results in a failing in said current authentication process.