Signals Intelligence (SIGINT) refers to the collection of electronic communications.
SIGINT is a broad discipline, and can include intelligence collection from various means including communications intelligence (COMMINT), electronic intelligence (ELINT) Radar and electronic warfare.
SIGINT works in various ways, and can provide significant intelligence. Most commonly though, SIGINT refers to the intercept of communications between individuals.
So, how does SIGINT work?
Intelligence organisations use SIGINT by gaining access to privileged telephone calls and monitoring the content of conversations for the purpose of collecting information.
Usually SIGINT targets are chosen due to their access to information, or their involvement in certain activities.
With the ability to intercept phone calls and communications data, intelligence analysts have the ability to analyse the information available and provide assessments on the activities of their targets.
SIGINT can involve the collection of communications data such as call logs, text messages, and geographical location data.
Access to SIGINT information provides intelligence analysts ability to determine who a target is talking to, when and where and assess the nature of relationships and their activities. All without being detected.
Furthermore, SIGINT has the potential to reveal geographic location of the target.