Patent ID: 8539235

Claim:
A method for operating a network, comprising a node and a system management device, the system management device comprising a root keying material being a set of functions each having a degree of complexity of α, and the node being provided with a node keying material share having a degree of complexity of α, the node keying material share being derived from the root keying material, the method comprising, upon receipt at the system management device of a request for an external user to gain access to the node: a) generating, by the system management device, an external user keying material share and an access identifier, the external user keying material share having a degree of complexity α and being generated from the root keying material; b) generating, by the system management device, an access keying material and an identifier of the node, the access keying material having a degree of complexity less than α and being generated from the external user keying material share; c) the system management device providing the external user with the access keying material share and the access identifier; d) the external user deriving a key from the access keying material share, and transmitting this key and the access identifier to the node; e) the node computing a key from the access identifier and the node keying material share; and f) the node comparing the key transmitted by the external user and the key computed by the node, so as to authenticate the external user.