Method and apparatus for generating keys for encoding data for transmission, a device identification is accessed and at least one key corresponding to the device identification. Data is encoded using at least one key. A message is transmitted from the first device to the second device, the message comprising a header comprising the device identification and a datafield comprising the encoded data. The second device uses the device identification received in the header of the message to determine the at least one key and decode the encoded data received in the datafield of the message using the determined at least one key.