The fixed-signature tracker was a tracking device that was developed for the New Jedi Order and the New Republic by Talon Karrde. During the Yuuzhan Vong War it was incorporated into the hulls of Republic ships and transports, including the Errant Venture and the Jade Sabre, so that the Galactic citizens could communicated without fear of their transmissions being detected by the Yuuzhan Vong.
Using a fixed-signature that passed through relays and the HoloNet, no one without a encryption key could decipher the messages.