Patent ID: 8458458

Claim:
A storage apparatus, comprising: a storage section; and an authentication unit for selectively preventing an information processing apparatus from accessing data stored in the storage section, the authentication unit comprising: a memory storing a program; and a processor configured to execute the program to cause the authentication unit to perform a method for selectively preventing the information processing apparatus from accessing the data, the method comprising: executing a mutual authentication protocol with the information processing apparatus; preventing the information processing apparatus from accessing the data when the mutual authentication protocol does not authenticate the information processing apparatus; comparing first information including a first revocation list stored in the memory with second information including a second revocation list received from the information processing apparatus; examining the first information to determine whether the information processing apparatus has been revoked; and selectively replacing the first information with the second information, based on the examination and at least one of a result of the execution of the mutual authentication protocol and a result of the comparison, wherein the first information is not replaced with the second information when the information processing apparatus has been revoked.