The Clandestine Dead Drop
Scott C. Krause | Monday, May 31, 2021
Keeping a secret is easy, communicating a secret is not.
Alice needs to get some information to Bob on the down low. It's best if you don't know the what or the why.
A dead drop is tradecraft in which a package is dropped at a designated place for pickup at a later time. The key here is that Alice and Bob do not actually meet. They are never in the same place at the same time. This affords them a degree of deniability and physical safety. The dead drop has evolved in the digital age. The preferred package is no longer microfiche but a PIN encrypted intelligent USB device.
Alice copies the documents onto a keypad encrypted USB drive, ejects and seals in its urban camouflaged, waterproof, and crushproof EDC Faraday capsule. She applies the serialized holographic tamper evident seal (sticky label).
Alice dresses to not impress. She removes jewelry and covers body ink. Her Wayfarers and black bike helmet thwart facial recognition.
Alice leaves her phone and ID at home and hops on a mountain bike and takes the scenic route (avoiding intersections with cameras) to the drop location. She inconspicuously attaches the capsule to a fixed object with the magnet or the attached carabiner. Our heroine takes a different route home.
Later that very night Bob arrives at the dead drop sans smartphone, smart watch, or Fitbit. He retrieves the package and vanishes. In the unfortunate event that Bob is captured the device should have a panic / duress password that is easy to remember (rubber-hose cryptanalysis). Entering this password would effectively shred the encryption key (we will give Bob a Dead Man's Switch (DMS) in a future story).
Bob safely retrieves the package. The unbroken seal suggests that it has not been tampered with. He enters an incorrect password once to be certain the device does not unlock. Bob understands that an adversary may have swapped the device with a faux unit custom programed to store and transmit all password attempts via bluetooth or net.
Later when Bob is safe from prying eyes and cameras he enters the correct password and boots an air-gapped laptop from the very same device.
The night becomes tomorrow. Data becomes information. Information becomes knowledge. Knowledge becomes wisdom. Wisdom fuels strategy.
Godspeed Alice and Bob and may your sweet nothings secure and endure.