A dead drop or dead letter box is a method of

espionage Espionage, spying, or intelligence gathering is the act of obtaining secret or confidential information ( intelligence) from non-disclosed sources or divulging of the same without the permission of the holder of the information for a tang ...

tradecraft Tradecraft, within the intelligence community, refers to the techniques, methods and technologies used in modern espionage (spying) and generally, as part of the activity of intelligence assessment. This includes general topics or techniques ( ...

used to pass items or information between two individuals (e.g., a case officer and an

agent Agent may refer to: Espionage, investigation, and law *, spies or intelligence officers * Law of agency, laws involving a person authorized to act on behalf of another ** Agent of record, a person with a contractual agreement with an insuranc ...

, or two agents) using a secret location. By avoiding direct meetings, individuals can maintain

operational security Operations security (OPSEC) is a process that identifies critical information to determine if friendly actions can be observed by enemy intelligence, determines if information obtained by adversaries could be interpreted to be useful to them, a ...

. This method stands in contrast to the live drop, so-called because two persons meet to exchange items or information. 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.

Considerations

The location and nature of the dead drop must enable retrieval of the hidden item without the operatives being spotted by a member of the public, the police, or other security forces—therefore, common everyday items and behavior are used to avoid arousing suspicion. Any hidden location could serve, although often a

cut-out Cut-out, cutout, or cut out may refer to: * Cutout animation * Cutout (electric power distribution), a combination fuse and knife switch used on power poles * Cutout (espionage), a mechanism used to pass information * Cut-out (philately), an impr ...

device is used, such as a loose brick in a wall, a (cut-out) library book, or a hole in a tree. A ''dead drop spike'' is a concealment device similar to a microcache. It has been used since the late 1960s to hide money, maps, documents,

microfilm Microforms are scaled-down reproductions of documents, typically either films or paper, made for the purposes of transmission, storage, reading, and printing. Microform images are commonly reduced to about 4% or of the original document size. ...

, and other items. The spike is water- and mildew-proof and can be pushed into the ground or placed in a shallow stream to be retrieved at a later time. Signaling devices can include a

chalk Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. C ...

mark on a wall, a piece of chewing gum on a

lamppost A street light, light pole, lamp pole, lamppost, street lamp, light standard, or lamp standard is a raised source of light on the edge of a road or path. Similar lights may be found on a railway platform. When urban electric power distribution ...

, or a

newspaper A newspaper is a periodical publication containing written information about current events and is often typed in black ink with a white or gray background. Newspapers can cover a wide variety of fields such as politics, business, spor ...

left on a

park bench A bench is a long seat on which multiple people may sit at the same time. Benches are typically made of wood, but may also be made of metal, stone, or other synthetic materials. Many benches have back rests while others do not and can be sat o ...

. Alternatively, the signal can be made from inside the agent's own home, by, for example, hanging a distinctively-colored towel from a balcony, or placing a potted plant on a window sill where it is visible to anyone on the street.

Drawbacks

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 Misinformation is incorrect or misleading information. It differs from disinformation, which is ''deliberately'' deceptive. Rumors are information not attributed to any particular source, and so are unreliable and often unverified, but can turn ...

to the enemy or to identify other operatives using it or ultimately to

booby trap A booby trap is a device or setup that is intended to kill, harm or surprise a human or another animal. It is triggered by the presence or actions of the victim and sometimes has some form of bait designed to lure the victim towards it. The trap m ...

it. There is also the risk that a third party may find the material deposited.

Modern techniques

On January 23, 2006, the Russian FSB accused Britain of using

wireless Wireless communication (or just wireless, when the context allows) is the transfer of information between two or more points without the use of an electrical conductor, optical fiber or other continuous guided medium for the transfer. The most ...

dead drops concealed inside hollowed-out rocks ("spy rock") to collect espionage information from agents in Russia. According to the Russian authorities, the agent delivering information would approach the rock and transmit data wirelessly into it from a hand-held device, and later, his British handlers would pick up the stored data by similar means. SecureDrop, initially called DeadDrop, is a software suite for teams that allows them to create a digital dead drop location to receive tips from whistleblowers through the Internet. The team members and whistleblowers never communicate directly and never know each other's identity, therefore allowing whistleblowers to dead-drop information despite the

mass surveillance Mass surveillance is the intricate surveillance of an entire or a substantial fraction of a population in order to monitor that group of citizens. The surveillance is often carried out by local and federal governments or governmental organizati ...

and privacy violations which had become commonplace in the beginning of the twenty-first century.

References

Bibliography

"Russians accuse 4 Britons of spying"
International Herald Tribune. January 24, 2006. News report on Russian discovery of British "wireless dead drop".
"Old spying lives on in new ways"
BBC. 23 January 2006.
Madrid suspects tied to e-mail ruse
International Herald Tribune. April 28, 2006.

* Robert Burnson, "Accused Chinese spy pleads guilty in U.S. 'dead-drop' sting", Bloomberg, 25 novembre 20

Considerations

Drawbacks

Modern techniques

See also

References

Bibliography

Further reading