Method for electronic transaction with digital signature

摘要

A mediation can be requested to a computer connected to a communications network when transacting parties A and B effect an electronic transaction and trouble takes place during the transaction. The transaction is effected by a procedure where the transacting party B transmits its preliminary digital signature to the transacting party A. When the transacting party B agrees with the contract document M transacting part A has submitted, the transacting parties A and B exchange their formal signature with each other. These signatures are obtained by coding data including a hash total h(M) obtained by transforming the contract docmument M, identifiers of the transacting parties A and B and a data identifier indicating whether the data are prepared for the preliminary on the formal signature by the public key cryptosystem using a secrete key for one of the transaction parties. When a trouble takes place, the mediation organization decodes the signatures submitted by the transacting parties as evidences by using a public key and checks as the basic of h(M) and the identifiers of the transacting parties whether the evidence data concern the same transaction or not. Finally, it decides the sort of the signatures based on the data identifiers and deduces a conclusion of the mediation.