Quantum key distribution

A method of authenticating a first node in a communications network with a remote node in the communications network comprising the step of connecting an authentication device to the first node, agreeing a quantum key between the first node and the remote node based on a quantum signal transmitted or received by the first node and performing an authentication step between the authentication device and the remote node on an encrypted channel wherein authentication between the authentication device and remote node is taken as authentication of the first node.

A method of authenticating a first node in a communication network comprising the steps of establishing a quantum link between a portable quantum key device and said first node and also establishing a communications link between said portable quantum key device and a remote node connected to the communication network, undertaking a quantum signal exchange on the quantum link between the portable quantum key device and the first node, communicating between the portable quantum key device and the remote node regarding the quantum signal exchange, said communication being encrypted using an authenticated cryptographic key known to the remote node and the portable quantum key device, and agreeing a quantum key between the first node and the remote node.