Interception

This can be either an active or passive process.

In a networked environment, a passive interception might involve someone who routinely monitors network traffic.

Active interception might include putting a computer system between sender and receiver to capture information as it is sent. From the perspective of interception, this process is covert. The last thing a person on an intercept mission wants is to be discovered.

Intercept missions can occur for years without the knowledge of the intercept parties.