SIGINT

SIGINT stands for Signals Intelligence, and refers to intelligence-gathering by interception of signals, whether by radio interception or other means.

As sensitive information is often encrypted, SIGINT often involves the use of cryptography. However, 'traffic analysis' can be used to gather information even when the messages themselves cannot be decrypted.

SIGINT activities have included:

• Ultra

See also:

• Espionage?