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 cryptanalysis. However, traffic analysis can be used to gather information even when the messages themselves cannot be decrypted.

Past and Present SIGINT Activities

• Ultra
• Purple code
• Echelon

Related Topics

• HUMINT - Intelligence gathered by a person on the ground
• IMINT - Intelligence gathered by satellite and aerial photography
• TECHINT - Technical intelligence

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In UNIX-derived operating systems, SIGINT stands for Signal Interrupt or Signal Interactive. It refers to the signal sent to a UNIX process by the kernel when the user on the process's terminal presses Control-C (On some systems, this is the "delete" character).