A person identification certificate link system forms a link between a person identification certificate which stores a template serving as person identification data and which is generated by a person identification certificate authority and a public key certificate which stores a public key, thereby specifying one certificate based on the other certificate. With this arrangement, a cryptographic key to the template stored in the person identification certificate can be specified. It is also possible to quickly obtain a combination of the person identification certificate and the public key certificate which are both utilized in transaction with a service provider, thereby improving the processing efficiency.