Satellite Command Uplink Authentication (2D)

This simulation visualizes the security model that protects a spacecraft's telecommand (TT&C) uplink — the same class of scheme standardized in CCSDS Space Data Link Security. A ground station transmits commands, each stamped with a monotonic counter and sealed with a keyed authentication tag; the onboard receiver recomputes the tag and checks the counter before ever letting a command reach the flight computer. A simulated attacker attempts replay, brute-force key guessing, or payload tampering, and every packet — legitimate or hostile — flies from the ground station to the orbiting satellite color-coded by the receiver's real verification outcome. A live strip beneath the orbit view turns the running accept/block/breach tally and the keyspace strength into a bar readout, so the effect of every slider is visible in two places at once.