http://bhqityoevbljuefl4m2khh3mw6ezcv7gg673qnyorka2o6loj3m6qead.onion/research
Laurens Sion, Koen Yskout, Dimitri Van Landuyt, Wouter Joosen, Risk-Based Design Security Analysis . Paper on threat modeling techniques using SecureDrop as an example. Saba Eskandarian, Henry Corrigan-Gibbs, Matei Zaharia, and Dan Boneh, Express: Lowering the Cost of Metadata-hiding Communication with Cryptographic Privacy (PDF).