Method of transferring digital certificate,apparatus for transferring digital certificate, and system, program, and recording medium for transferring digital certificate

A method of transferring digital certificates from a digital-certificate transferring apparatus to a communications apparatus which is a communications counterpart of the digital-certificate transferring apparatus, comprising:

• using two types of digital certificates having different validity periods for authenticating the communications counterpart when communicating;
• and
• authenticating the communications counterpart using a long-term certificate having a longer validity period of said two types of digital certificates, and transferring a normal certificate having a shorter validity period of said two types of digital certificates to the communications counterpart when the authenticating succeeds during the validity period of said long-term certificate;
• and
• receiving a first normal certificate, at an address of the digital-certificate transferring apparatus which corresponds to the first normal certificate, from said communications counterpart, and when, based on said received first normal certificate, it is determined to be necessary to transfer a second normal certificate to the communications counterpart for the communications counterpart to use when communicating with the digital-certificate transferring apparatus, transferring to the communications counterpart the second normal certificate along with an address of the digital-certificate transferring apparatus corresponding to the second normal certificate for the communications counterpart to use when communicating with the digital-certificate transferring apparatus, said second normal certificate having a validity period shorter relative to said long-term certificate, and being different from said first normal certificate.

An apparatus for transferring digital certificates to a communications apparatus which is a communications counterpart, comprising:

• means for using two types of digital certificates having different validity periods for authenticating the communications counterpart when communicating;
• first transferring means for authenticating the communications counterpart using a long-term certificate having a longer validity period of said two types of digital certificates, and transferring a normal certificate having a shorter validity period of said two types of digital certificates to the communications counterpart when the authenticating succeeds during the validity period of said long-term certificate;
• and
• second transferring means for receiving a first normal certificate, at an address of the apparatus which corresponds to the first normal certificate, from said communications counterpart, and when, based on said received first normal certificate, it is determined to be necessary to transfer a second normal certificate to the communications counterpart for the communications counterpart to use when communicating with the apparatus, transferring to the communications counterpart the second normal certificate along with an address of the apparatus corresponding to the second normal certificate for the communications counterpart to use when communicating with the apparatus, said second normal certificate having a validity period shorter relative to said long-term certificate, and being different from said first normal certificate.

A system for transferring digital certificates, comprising:

• a digital-certificate transferring apparatus for transferring a digital certificate to a communications apparatus;
• and
• the communications apparatus to be a communications counterpart of the digital-certificate transferring apparatus,
• the digital-certificate transferring apparatus further comprising:
• first transferring means for authenticating the communications counterpart using a common certificate being a digital certificate without apparatus-identifying information and transferring a normal certificate being a digital certificate with information identifying said communications counterpart to the communications counterpart when the authenticating succeeds;
• and
• second transferring means for receiving a first normal certificate, at an address of the apparatus corresponding to the first normal certificate, from said communications counterpart, and when, based on said received first normal certificate, it is determined to be necessary to transfer a second normal certificate to the communications counterpart for the communications counterpart to use when communicating with the apparatus, transferring to the communications counterpart along with the information identifying the communications counterpart and an address of the apparatus corresponding to the second normal certificate for the communications counterpart to use when communicating with the apparatus, said second normal certificate being a different type than said first normal certificate;
• and,
• the communications apparatus further comprising:
• means for receiving each one of said first normal certificate and said second normal certificate from said certificate-transferring means so as to store the received certificate.

A system for transferring digital certificates, comprising:

• a digital-certificate transferring apparatus for transferring a digital certificate to a communications apparatus;
• and
• the communications apparatus to be a communications counterpart of the digital-certificate transferring apparatus,
• the digital-certificate transferring apparatus further comprising:
• means for using two types of digital certificates having different validity periods for authenticating the communications counterpart when communicating;
• first transferring means for authenticating the communications counterpart using a long-term certificate having a longer validity period of said two types of digital certificates, and transferring a normal certificate having a shorter validity period of said two types of digital certificates to the communications counterpart when the authenticating succeeds during the validity period of said long-term certificate;
• and
• second transferring means for receiving a first normal certificate, at an address of the apparatus which corresponds to the first normal certificate, from said communications counterpart, and when, based on said received first normal certificate, it is determined to be necessary to transfer a second normal certificate to the communications counterpart for the communications counterpart to use when communicating with the apparatus, transferring to the communications counterpart the second normal certificate along with an address of the apparatus corresponding to the second normal certificate for the communications counterpart to use when communicating with the apparatus, said second normal certificate having a validity period shorter relative to said long-term certificate, and being different from said first normal certificate;
• and,
• the communications apparatus further comprising:
• means for receiving said each one of said first normal certificate and said second normal certificate from said certificate-transferring means so as to store said received certificate.

A computer readable storage medium encoded with computer executable instructions, which when executed by a computer, cause the computer to function as a digital-certificate transferring apparatus for transferring a digital certificate to a communications apparatus to be a communications counterpart, comprising:

• first transferring means for authenticating the communications counterpart using a common certificate being a digital certificate without apparatus-identifying information and transferring a normal certificate being a digital certificate with information identifying said communications counterpart to the communications counterpart when the authenticating succeeds;
• and
• second transferring means for receiving a first normal certificate, at an address of the apparatus corresponding to the first normal certificate, from said communications counterpart, and when, based on said received first normal certificate, it is determined to be necessary to transfer a second normal certificate to the communications counterpart for the communications counterpart to use when communicating with the apparatus, transferring to the communications counterpart along with the information identifying the communications counterpart and an address of the apparatus corresponding to the second normal certificate for the communications counterpart to use when communicating with the apparatus, said second normal certificate being a different type than said first normal certificate.

A computer readable storage medium encoded with computer executable instructions, which when executed by a computer, cause the computer to function as a digital-certificate transferring apparatus for transferring a digital certificate to a communications apparatus to be a communications counterpart, comprising:

• means for using two types of digital certificates having different validity periods for authenticating the communications counterpart when communicating;
• first transferring means for authenticating the communications counterpart using a long-term certificate having a longer validity period of said two types of digital certificates, and transferring a normal certificate having a shorter validity period of said two types of digital certificates to the communications counterpart when the authenticating succeeds during the validity period of said long-term certificate;
• and
• second transferring means for receiving a first normal certificate, at an address of the apparatus which corresponds to the first normal certificate, from said communications counterpart, and when, based on said received first normal certificate, it is determined to be necessary to transfer a second normal certificate to the communications counterpart for the communications counterpart to use when communicating with the apparatus, transferring to the communications counterpart the second normal certificate along with an address of the apparatus corresponding to the second normal certificate for the communications counterpart to use when communicating with the apparatus, said second normal certificate having a validity period shorter relative to said long-term certificate, and being different from said first normal certificate.