Each packet is prefixed with a 8 byte timestamp. It consists of the number of seconds since the 1st of January 1970 and a 16 bit counter. The timestamp and the data are used as input for a SHA-256 hash. This hash is used to calculate a 256 bit elliptic curve signature. By including the timestamp we ensure that playback of previously recorded packets can be detected.
|8 byte timestamp||data||64 byte signature|
|48 bit second counter||16 bit packet counter||data||256 bit elliptic curve signature based on SHA-256 hash|