The vibration of a tire 10 of a running vehicle in the circumferential direction or the width direction is detected by a road surface condition estimating tire 10, provided with an acceleration sensor 11 and a signal processing unit 12. A recording tape cartridge includes: a case that accommodates a reel on which a recording tape is wound; a security tag having a substantially pillar shape, that is provided within the case, and that is adapted to transmit to and receive from an exterior; and a holding portion formed in the case, that holds the security tag by having the security tag fitted with the holding portion. As such, the proxy creates an overlapping chain of digitally signed audit records subsets.