Patent ID: 8683202

Claim:
A method for verifying authenticity of messages exchanged between a mobile node and a home agent in accordance with a mobile Internet Protocol, with a cryptographic method used for verifying the authenticity of the messages being agreed between the mobile node and the home agent, comprising: creating, by the mobile node, a registration request containing information on a plurality of cryptographic methods supported by the mobile node; providing authentication data related to a first cryptographic method used to protect the registration request, for verification by the home agent of authenticity of the registration request; sending the registration request including the authentication data, from the mobile node to the home agent; checking, by the home agent, authenticity of the registration request; if the home agent establishes the authenticity of the registration request, selecting, by the home agent, a second cryptographic method from the plurality of cryptographic methods indicated by the information contained in the registration request as a mutually supported cryptographic method for the mobile node and the home agent; registering, by the home agent, the mobile node and setting up at least one message security association between the mobile node and the home agent using the second cryptographic method; and sending a registration reply, from the home agent to the mobile node, indicating whether the registration of the mobile node is successful and notifying the mobile node about said selecting of the second mutually-supported cryptographic method if the home agent establishes the authenticity of the registration request.