Patent ID: 8271804

Claim:
A log management apparatus comprising: a processing unit; a storage unit having machine readable instructions stored thereon that when executed by the processing unit cause the apparatus to receive a signature-bound event log created by an information processing device through a network, the signature-bound event log being created by binding an event log of each event that occurred and a digital signature created by encrypting, with a private key of the information processing device, a hash value created from the event log; decrypt the hash value from the digital signature bound in the received signature-bound event log with a public key of the information processing device; create a new hash value from the event log in the received signature-bound event log; verify coincidence between the decrypted hash value and the new hash value; and authenticate the signature-bound event log if the decrypted hash value coincides with the new hash value; and a log storage that stores the signature-bound event log with a managing-side digital signature being bound thereto when the signature-bound event log has been successfully authenticated, and stores the signature-bound event log without binding the managing-side digital signature when the signature-bound event log has not been successfully authenticated.