Abstract: A method for protecting data transmission in an ad hoc network including nodes, each node including a private key, a public key and a certificate of the public key signed by a certification authority, the method including transmitting by the first node to the second node: a first message signed with the private key of the first node; a third message containing a first set of initialization data including: a first certificate including the public key of the first node, signed by the certification authority; a second data set including the IP address of the first node; and the first certificate associated with the IP address of the first node, wherein the second data set is signed with the private key of the first node.