deaddrop

Working repository for the dead drop project

Example Communication

Here's a communication between senders Alice and Bob (this command line tool to store/retrieve from the drive is called deaddrop in this example):

• alice stops by the space to drop off a file on the drive

• 30GB tarball is encrypted using bob's public key to file ss.gpg

    alice$ gpg --encrypt --recipient 'bob' --output ss.gpg state-secrets.tar.gz
  

• alice stores ss.gpg

• deaddrop stores 0xDEADBEEF, and the filesize, 30GB, in a row in the database

• deaddrop writes the file as a raw byte[] starting at 0xDEADBEEF (conceptually)

    alice$ deaddrop --store ss.gpg
    OK, locator = 0xDEADBEEF
    alice$ 
  

• bob gets a text from alice on his phone: 0xDEADBEEF, which is difficult to understand out of context

• bob visits the space and hooks up to drive

• bob accesses file at locator 0xDEADBEEF

    bob$ deaddrop --retrieve 0xDEADBEEF --output tmp.encrypted
    OK, size = 30GB
    bob$
  

• bob can then decrypt the file (he also knows it's a tarball ahead of time)

    bob$ gpg --decrypt --output ss.tar.gz tmp.encrypted
    bob$ tar -xzvf ss.tar.gz
    bob$ 
  

This way, if Eve wants to intercept ss.tar.gz, Eve needs to know the locator (0xDEADBEEF).

Even with this information, Eve doesn't know either who uploaded the file or who the intended recipient is, so it's not possible to decrypt the file.

As a bonus, if only one of either the sender or the recipient's private keys are compromised, then the file remains encrypted to Eve (if either the sender or recipient remain unknown to Eve).