Computer-readable recording medium storing update program and update method, and computer-readable recording medium storing management program and management method

An update method performed by a computer, comprising:

• sending an issuing request of a second public key certificate to a server in response to a connection to the server at an initial use of a first public key certificate, to which a validity date is attached;
• receiving the second public key certificate from the server;
• storing the second pubic key certificate in a storage part;
• and
• conducting a connection confirmation using the second public key certificate in a shorter term than the first public key certificate is to be estimated in a secure communication using the first public key certificate prior to the validity date after receiving the second public key certificate.

A non-transitory computer-readable recording medium storing therein a management program for multiple public key certificates used to confirm a validity of a client terminal sending request data and the validity of the request data, the management program causing a computer to execute a process comprising:

• sharing a temporary common key with the client terminal in response to a connection to the client terminal at an initial use of a first public key certificate, to which a validity date is attached;
• generating a second public key certificate with respect to an issuing request of the second public key certificate from the client terminal;
• encrypting the second public key certificate by using the temporary common key;
• and
• sending the encrypted second public key certificate to the client terminal;
• and
• setting the second public key certificate as the first public key certificate upon a connection confirmation from the client terminal using the second public key certificate in a shorter term than the first public key certificate is to be estimated in a secure communication using the first public key certificate prior to the validity date after receiving the second public key certificate,
• wherein the first public key certificate remains valid during the validity date in a communication connection to the client terminal.

A management method performed by a computer to maintain multiple public key certificates used to confirm a validity of a client terminal sending request data and the validity of the request data, the management method comprising:

• sharing a temporary common key with the client terminal in response to a connection to the client terminal at an initial use of a first public key certificate, to which a validity date is attached;
• generating a second public key certificate with respect to an issuing request of the second public key certificate from the client terminal;
• encrypting the second public key certificate by using the temporary common key;
• sending the encrypted second public key certificate to the client terminal;
• and
• setting the second public key certificate as the first public key certificate upon a connection confirmation from the client terminal using the second public key certificate in a shorter term than the first public key certificate is to be estimated in a secure communication using the first public key certificate prior to the validity date after receiving the second public key certificate,
• wherein the first public key certificate remains valid during the validity date in a communication connection to the client terminal.