A computer-readable recording medium storing a program to be executed by a first apparatus in a system of issuing attribute certificate information of each user, the program including instructions for causing a processor of the first apparatus to execute processing including: obtaining, from a second apparatus in the system, a value unique to an identifier that uniquely identifies a user, the second apparatus being a device capable of verifying authenticity of an electronic document to be signed; creating certificate information that includes attribute information identified from the attribute certificate information, certification information that certifies the attribute information, and the obtained value; generating an electronic signature for the electronic document and the certificate information using a private key that corresponds to the identifier; and outputting the electronic document and the certificate information to which the generated electronic signature is attached in association with the identifier.