Transmission Security Law and Legal Definition

Transmission security (TRANSEC) means the concealment of electrically transmitted message by adopting measures that are designed to protect transmission from interception and exploitation by means other than cryptographic analysis. Generally, TRANSEC is a constituent of communications security (COMSEC). TRANSEC is secured through burst encoding, frequency hopping, or spread spectrum methods where the required pseudorandom sequence generation is controlled by a cryptographic algorithm and key. Such keys are known as transmission security keys (TSK).

The objectives of transmission security are low probability of interception (LPI), low probability of detection (LPD), and antijam which means resistance to jamming (EPM or ECCM).