Abstract: An apparatus includes a digital signature verification data embedding unit and a signing unit. The digital signature verification data embedding unit is configured to embed digital signature verification data for use in verification of a digital signature for an electronic document into the electronic document. The signing unit is configured to sign the electronic document with a digital signature whose validity can be verified using digital signature verification data embedded in the electronic document.

Abstract: When an encrypted electronic document is stored, input of a first password that is for decrypting the electronic document is allowed and input of time information on which decryption of the electronic document is permitted utilizing the first password is allowed. The first password and the time information that have been input are stored in a storage unit in association with the encrypted electronic document. If it is determined that the date and time stored in the storage unit has passed, the encrypted electronic document that has been stored in the storage unit is decrypted utilizing the first password. The decrypted electronic document is re-encrypted using a second password.