To intentionally prepare authentication information from inoperable time information.

An information processor 1 including a timing mechanism is provided externally with a timing and authenticating device 2 having a timing mechanism part 21 offering time information than cannot be operated intentionally and an authentication mechanism part 22 offering authentication information, prepares authentication source information consisting of the time information transmitted from the part 21, in response to a time request and externally inputted user identification information and transmits the authenticating source information to the part 22. Although the part 22 prepares the authentication information from the time information and the user identification information which are the authentication source information, the part 22 prepares and transmits the authentication information such as those which change with the time information as a base, so that the processor 1 receives the transmitted authentication information and issues the authentication information as a certificate.