Dead drop
A dead drop or dead letter box is a method of espionage tradecraft used to pass items or information between two individuals (e.g., a case officer and an agent, or two agents) using a secret location. By avoiding direct meetings, individuals can maintain operational security. This method stands in contrast to the live drop, so-called because two persons meet to exchange items or information.
For a USB device used as a public dead drop, see USB dead drop.Spies and their handlers have been known to perform dead drops using various techniques to hide items (such as money, secrets or instructions) and to signal that the drop has been made. Although the signal and location by necessity must be agreed upon in advance, the signal may or may not be located close to the dead drop itself. The operatives may not necessarily know one another or ever meet.[1][2]
Drawbacks[edit]
While the dead drop method is useful in preventing the instantaneous capture of either an operative/handler pair or an entire espionage network, it is not without disadvantages. If one of the operatives is compromised, they may reveal the location and signal for that specific dead drop. Counterintelligence can then use the dead drop as a double agent for a variety of purposes, such as to feed misinformation to the enemy or to identify other operatives using it or ultimately to booby trap it.[3] There is also the risk that a third party may find the material deposited.