A user registration processor unit registers the user registration information to the database, which includes the public key certification acquired from the certification authority that has jurisdiction over each party by the request from the transaction party including seller, buyer, and transportation company. A transfer registration processor unit changes the access right holder and the cargo owner of the shipment information registered to the database at the start of transaction in compliance with the request for request for changing registration of the party with the digital signature and public key certification attached. A verification processor unit achieves the transfer registration with legal binding power by verifying that the digital signature attached to the request for request for changing registration has been prepared by the private key which makes a pair with the public key certificate registered to the database and receiving the approval of the other party.