The invention relates to a generic bootstrapping architecture protocol. Method and system for communicating securely with a user equipment, UE, using generic bootstrapping architecture, GBA, the system comprising a bootstrapping server function, BSF. A proxy server configured to receive messages from a user equipment, UE, in a first format. Convert the received messages from the first format to a second format. Transmit the received UE messages to a bootstrapping server function, BSF, in the second format. Receive messages from the BSF, in a third format. Convert the messages received from the BSF from the third format to a fourth format. Transmit the received BSF messages to the UE in the fourth format.