Transmission Security (TRANSEC)

Measures (security controls) applied to transmissions in order to prevent interception, disruption of reception, communications deception, and/or derivation of intelligence by analysis of transmission characteristics such as signal parameters or message externals.

Note: TRANSEC is that field of COMSEC which deals with the security of communication transmissions, rather than that of the information being communicated.
SOURCE: CNSSI-4009