Patent ID: 7752465

Claim:
A platform configuration measurement device comprising: a platform configuration register (PCR register) specified in the Trusted Computing Group specification, the PCR register storing content relating to configuration information of a computing platform; at least one processor configured: for executing extension processing in which a predetermined operation of concatenation of an additional value to the content of the PCR register is performed on the content of the register by using a given random value, wherein a hash value is obtained by applying a predetermined hash function to the given random value obtained by the predetermined operation, and the hash value is set for a new content of the PRC register; for obtaining measured values, corresponding to predetermined components constituting a platform, by sequentially making a measurement on the predetermined components, and executing the extension processing using the measured values as the additional values; for performing random extension for executing the extension processing repeatedly at a predetermined timing using the given random value as the additional value; for sending a third party the content of the PRC register together with a log storing records of extension processes executed in the device, the content of the register and the log being digitally signed, in response to an authentication request including a nonce from a client; for receiving a digitally signed credential sent from the third party in response to the sending action, the credential vouching for trustworthiness of a platform configuration according to the content of the register to be appended; and for sending the client the received digitally signed credential with the digitally signed nonce and content of the register; and a platform configuration measurement program causing the computer platform to operate functioning for constituting the platform configuration measurement device.