| 摘要 |
PROBLEM TO BE SOLVED: To enable determination of validity for electronic data having an electronic signature with an expired valid period.SOLUTION: An electronic data receiver identifies a public key, associated with an electronic signature added to received electronic data, within one or more public keys having a valid period. If the identified public key is not valid, the receiver transmits a re-transmission request, and performs a process for determining validity of the electronic data based on whether a re-transmission of the electronic data is performed or not according to the re-transmission request. If a transmitter of the electronic data has transmitted electronic data in the past, corresponding to the re-transmission request according to the reception of the re-transmission request, then the transmitter performs a process to re-transmit the electronic data to the receiver. |
