Time proving device, time certification request accepting apparatus, time proven method, time certification request acceptance method, time certification program, time certification request acceptance program, time certification verification program, and program recording medium

摘要

PROBLEM TO BE SOLVED: To perform time certification with an accurate time, even if there are a number of time certification requests simultaneously from users by utilizing the Merkle hash tree in a time stamp system, based on a public key.;SOLUTION: A time certification apparatus 1 comprises a transmitting/receiving part 11 for exchanging data between a time information providing device 2 and client devices 3i via a computer network 4; a time certification request editing part 12 for editing a message digest transmitted from the client devices 3i as time certification requests, using the Merkle hash tree; a time information acquiring part 13 for acquiring time information from the time information providing device 2, when creating a time certificate; a time certification creating part 14 for creating the time certificate by adding the time information, that is acquired by the time information acquiring part 12, to the message digest edited by the time certification request editing part 12; and a time certificate storage part 15 for storing the time certificate created by the time certification creating part 14.;COPYRIGHT: (C)2005,JPO&NCIPI