Pairing a medical apparatus with a control unit

A medical instrument, wherein the medical instrument comprises a medical appliance and a control unit, wherein the medical appliance is battery powered by a first battery, wherein the control unit is battery powered by a second battery, wherein the medical appliance comprises an electronic portion and a subcutaneous portion, wherein the electronic portion comprises a first processor (132) and a first memory, wherein the first memory contains a onetime password wherein the first memory further contains an implementation of a password-authenticated key agreement algorithm, wherein the first memory further contains first machine executable instructions,

• wherein the control unit comprises a second processor and a second memory, wherein the control unit comprises a data entry interface, wherein the second memory contains the implementation of the password-authenticated key agreement algorithm, wherein the second memory further contains second machine executable instructions,
• wherein the medical appliance comprises a first Bluetooth communication module, wherein the control unit further comprises a second Bluetooth communication module, wherein the first Bluetooth communication module and the second Bluetooth communication module are operable for forming a wireless communication channel between the medical appliance and the control unit,
• wherein execution of the second machine executable instructions cause the second processor to receive the onetime password into the data entry interface,
• wherein execution of the second machine executable instructions and the first machine executable instructions cause the first processor and the second processor to generate a Bluetooth encryption key 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, wherein the control unit initiates execution of the password-authenticated key agreement algorithm,
• wherein execution of the first machine executable instructions cause the first processor to store the Bluetooth encryption key in the first memory;
• wherein execution of the first instructions further cause the first processor to disable the password-authenticated key agreement algorithm in the first memory after storing the Bluetooth encryption key in the first memory,
• wherein execution of the second machine executable instructions cause the second processor to store the Bluetooth encryption key in the second memory,
• wherein execution of the second machine executable instructions and the first machine executable instructions cause the first processor and the second processor to establish an encrypted Bluetooth communication channel using the first Bluetooth communication module and the second Bluetooth communication module, wherein the encrypted Bluetooth communication channel is the wireless communication channel encrypted using the Bluetooth encryption key.