Dead drop

For a USB device used as a public dead drop, see USB dead drop. For the 2023 novel by M. P. Woodward, see Dead Drop (novel).

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 3 in (7.6 cm) 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 case officer and an agent, or two agents) via a secret location. 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.

Spies and their handlers have been known to perform dead drops using various techniques to hide items (such as money, information, 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.

Dead drops are sometimes used for the sale of narcotics. This method of illegal drug distribution has seen a rise in popularity on Darknet drug markets (DNMs) which offer escrow services, facilitating trust between buyers and sellers. This method of distribution first became popular on Russian DNMs.