Validation Server, Program and Verification Method

A program that makes a computer function as a validation server for verifying a public key certificate, wherein the program makes the computer function as:

• a storage unit, which stores first identification information determined uniquely by key information of a certificate authority and a hash algorithm, respectively;
• and
• a processing unit, which judges that validation requested by a validation request can be performed if the storage part stores first identification information corresponding to second identification information determined by key information of a certificate authority, included in the validation request and a hash algorithm used in producing the validation request.

A verification method for verifying a public key certificate by a validation server comprising a storage part that stores first identification information determined uniquely by key information of a certificate authority and a hash algorithm, and a processing part, wherein:

• the verification method comprises a process in which the processing part judges that validation requested by a validation request can be performed if the storage part stores first identification information corresponding to second identification information, determined by key information of a certificate authority, included in the validation request, and a hash algorithm used in producing the validation request.