Patent ID: 7181614

Claim:
A method for establishing security in an ad hoc communication network, the ad hoc communication network comprising a set of communication nodes, at least two nodes of the set of communication nodes having a mutual trust relation and comprising a trust group, the trust relations being created with public keys, and at least one additional node, the at least one additional node being a candidate node for joining the trust group within the ad hoc communication network, the nodes having authority to delegate trust to nodes of the set of communication nodes within the trust group, the method comprising the steps of: receiving a request from the candidate node to join the trust group within said ad hoc communication network wherein said ad hoc communication network does not include a separate certificate authority; identifying any node within the trust group having a trust relation with the candidate node, the node having the trust relation with the candidate node being an X-node; and distributing trust relations between all members in the trust group and the candidate node by means of the X-node distributing the public key associated with said candidate node to said all members of the trust group and wherein X-node further sending a signed message comprising a list of nodes that the X-node trusts within the ad hoc communication network and all corresponding public keys to the candidate node.