Patent ID: 8522009

Claim:
A device management system including a site monitoring apparatus that communicates with a management server via an internet, and a plurality of monitoring target devices that are to be connected to the site monitoring apparatus, wherein the site monitoring apparatus comprises at least one processor functioning as: a holding unit that holds a secret key that is paired with a public key held by each of the monitoring target devices; an issue unit that issues, within the site monitoring apparatus, a server certificate and a root certificate that are for performing secure communication with each of the monitoring target devices; a signature unit that issues, with use of the secret key, a digital signature based on communication destination information in which the site monitoring apparatus is a communication destination and the root certificate issued by the issue unit; and a transmission unit that transmits the communication destination information, the root certificate issued by the issue unit, and the digital signature issued by the signature unit to each of the monitoring target devices, and wherein each of the monitoring target devices comprises at least one processor functioning as: a holding unit that holds the public key paired with the secret key held by the site monitoring apparatus; a reception unit that receives the communication destination information, the root certificate, and the digital signature from the site monitoring apparatus; an authentication unit that performs authentication on the digital signature received by the reception unit with use of the public key; and a communication unit that, in the case of successful authentication performed by the authentication unit, changes a communication destination for device monitoring information from the management server to the site monitoring apparatus and performs secure communication with the site monitoring apparatus, with use of the communication destination information and the root certificate received by the reception unit; wherein the communication destination information is URL information, wherein the processor of the site monitoring apparatus further functions as a confirmation unit that inquires whether each of the monitoring target devices has a transmission function for transmitting device monitoring information by a web service with use of the URL information, wherein the transmission unit transmits the communication destination information, the root certificate, and the digital signature to the monitoring target devices that have been confirmed as having the transmission function by the inquiry performed by the confirmation unit, and wherein the transmission unit does not transmit the communication destination information, the root certificate, and the digital signature to the monitoring target devices that have been confirmed as not having the transmission function by the inquiry performed by the confirmation unit.