To provide a system or the like capable of eliminating the need for a client apparatus to take a measure for time stamp verification such as storage of verification information in advance and preventing an electronic signature and a time stamp acquired in the past from being not verifiable.

The client apparatus 200 extracts an electronic certificate associated with an electronic signature and/or an electronic certificate associated with a time stamp applied to verification object data issued by an authentication agency apparatus 500 to generate a verification information issue request. A time stamp verification station apparatus 100 transmits an electronic certificate associated with the collated electronic signature and/or an electronic certificate associated with the collated time stamp, an electronic certificate of the authentication agency apparatus 500 existing in an authentication path of the electronic certificates above, and a verification information issue acknowledgement including expired electronic certificate and time stamp to the client apparatus 200.