Patent ID: 7457416

Claim:
A method of distributing key information by securely transmitting light information in a network along a path comprised of a plurality of network devices, said network devices comprising a plurality of switching devices, said method comprising: specifying a plurality of user devices connected with the network, said user devices constituting a secure communication group; setting up a plurality of paths through said network by sending at least one setup message from the respective user devices to said network devices, based on said setup message, configuring said network devices to direct said light information along a corresponding one of said paths, each of said paths being an end-to-end path between each of said user devices and a key distribution center device connected with the network using said switching devices; establishing a plurality of user keys, each user key corresponding to a respective user device, by sending the light information using randomly selected quantum bases through said paths, each of said user keys being acquired by said respective user devices and the key distribution center device; determining a shared secret key at the key distribution center device; and notifying each of said user devices of the shared secret key by sending the result of a calculation based on the shared secret key and the corresponding user key for each respective user device through the network.