Editing Dead drop (section)

{{short description|Method of espionage tradecraft}}
{{for|a USB device used as a public dead drop|USB dead drop}}
[[File:Aldrich Ames mailbox.jpg|thumb|This (replacement) mailbox is identical to, and in the same location of, one that convicted spy [[Aldrich Ames]] used to signal his Russian counterparts. Ames would place a horizontal chalk mark about {{convert|3|in|cm|abbr=on}} long above the [[USPS]] logo.]]

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 [[Agent handling#Case officer|case officer]] and an [[Espionage#Agents in espionage|agent]], or two agents) via a secret location.<ref>{{Cite web |last= |first= |title=New Dead drop techniques used by Security Agencies |url=https://thehackernews.com/2012/11/new-dead-drop-techniques-used-by.html |access-date=2025-04-08 |website=The Hacker News |language=en}}</ref> By avoiding direct meetings, individuals can maintain [[operational security]]. This method stands in contrast to the '''live drop''', which involves a face-to-face exchange.<ref>{{Cite web |last=Black |first=Bryan |date=2011-03-17 |title=DIY Dead Drop Devices to Hide and Pass Messages like a Spy |url=https://www.itstactical.com/intellicom/tradecraft/diy-dead-drop-devices-to-hide-and-pass-messages-like-a-spy/ |access-date=2025-04-08 |website=ITS Tactical |language=en-US}}</ref>

[[Espionage|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 or meet each other.<ref>Robert Wallace and H. Keith Melton, with Henry R. Schlesinger, ''Spycraft: The Secret History of the CIA's Spytechs, from Communism to al-Qaeda'', New York, Dutton, 2008. ISBN 0-525-94980-1. Pp. 43-44, 63, and 74-76.</ref><ref>Jack Barth, ''International Spy Museum Handbook of Practical Spying'', Washington DC, National Geographic, 2004. ISBN 978-0-7922-6795-9. Pp. 119-125.</ref>