Patent ID: 7502930

Claim:
A method of providing secure communications between a first and a second communications unit in a short range wireless system, the method comprising a key exchange between the first and second communications units resulting in a shared secret key, the key exchange including a user interaction, the method comprising the steps of: prior to establishing a communications link between the first and second communications units, providing, at least partly by means of a user interaction, a passcode to the first and second communications units in an initial registration process; generating a first contribution to the shared secret key by the first communications unit and a second contribution to the shared secret key by the second communications unit; transmitting each generated contribution to the corresponding other communications unit; authenticating, using a message authentication code and the passcode, the transmitted first and second contributions by the corresponding receiving communications unit; and establishing said shared secret key by each of the communications units from at least the corresponding received first or second contribution, only if the corresponding received contribution is authenticated successfully.