| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an e-mail terminal device which can perform such processings as printing or storage, only of an e-mail having signatures or an e-mail with the signature of a reliable certificate authority. <P>SOLUTION: When an e-mail is received by the e-mail terminal device, a decision is made whether the e-mail requires a signature (S202) and if it requires signature, decisions are made whether a signature has been given, verification result of the signature is valid, and a certificate authority issuing a public key used for verification of the signature is reliable (S203, 205, 206). When a signature has not not been imparted, the signature is invalid or the certificate authority is not reliable; and printing will not be performed and an e-mail requesting retransmission of a signed e-mail or an e-mail signed with the private key of a reliable certificate authority is transmitted to the source (S207). <P>COPYRIGHT: (C)2006,JPO&NCIPI |
