Patent attributes
The invention provides for method of operating a medical instrument (100, 200, 400, 500, 600, 700) comprising a battery powered medical appliance (104) and a control unit (102). Both have Bluetooth communication modules. A first memory of the medical appliance contains a onetime password (210) and of a password-authenticated key agreement algorithm (212). The control unit has a second memory (223) with an implementation of the password-authenticated key agreement algorithm (212′). The method comprises entering (300) the onetime password into the data entry interface (140, 221, 504, 604) of the control unit. The method further comprises generating (302) a Bluetooth encryption key (218) by the medical appliance and the control unit with the onetime password by exchanging data across the wireless communication channel by executing the password-authenticated key agreement algorithm. The method further comprises storing (304) the Bluetooth encryption key in the first memory. The method further comprises disabling (306) the password-authenticated key agreement algorithm in the first memory after storing the Bluetooth encryption key in the first memory. The method further comprises storing (308) the Bluetooth encryption key in the second memory. The method further comprises establishing (310) an encrypted Bluetooth communication channel using the first Bluetooth communication module and the second Bluetooth communication module. The encrypted Bluetooth communication channel is the wireless communication channel encrypted using the Bluetooth encryption key.
