Apparatus and methods for encrypted communication

A communication system comprising a first device, a second device, and a third device, wherein:

• the first device comprises a first-device-memory, storing first-device-specific identification data;
• the second device comprises a second-device-memory, storing second-device-specific identification data;
• the first device is configured to receive a copy of the second-device-specific identification data from the second device and to store the copy in the first-device-memory of the first device;
• the second device is configured to receive a copy of the first-device-specific identification data from the first device and to store the copy in the second-device-memory of the second device;
• the first device is configured to derive a first encryption key from the first-device-specific identification data and the received copy of the second-device-specific identification data;
• the second device is configured to derive the first encryption key from the second-device-specific identification data and the received copy of the first-device-specific identification data;
• the first device is configured to encrypt transmission data using the first encryption key and to transmit the encrypted transmission data to the second device;
• the second device is configured to receive the encrypted transmission data from the first device and to decrypt the encrypted transmission data using the first encryption key;
• the third device is configured to communicate at least with the second device and with a remote server, and wherein the third device is trusted by the second device, the third device being arranged and configured to mediate communication between the second device and the first device;
• such that when in a provisioning phase, the third device is configured to communicate at least with the second device and the remote server in order to determine whether the received copy of the first-device-specific identification data corresponds to first-device-specific identification data stored on the remote server,
• wherein the second device is configured not to proceed to derive the first encryption key if the copy of the first-device-specific identification data does not correspond to the first-device-specific identification data stored on the remote server.