A secure submission system for online whistleblowing platforms

Whistleblower laws protect individuals who inform the public or an authority about governmental or corpo-rate misconduct. Despite these laws, whistleblowers frequently risk reprisals and sites such as WikiLeaks emerged to provide a level of anonymity to these indi-viduals. However, as countries increase their level of network surveillance and Internet protocol data reten-tion, the mere act of using anonymizing software such as Tor, or accessing a whistleblowing website through an SSL channel might be incriminating enough to lead to investigations and repercussions. As an alternative sub-mission system we propose an online advertising network called AdLeaks. AdLeaks leverages the ubiquity of un-solicited online advertising to provide complete sender unobservability when submitting disclosures. AdLeaks ads compute a random function in a browser and sub-mit the outcome to the AdLeaks infrastructure. Such a whistleblower’s browser replaces the output with en-crypted information so that the transmission is indistin-guishable from that of a regular browser. Its back-end design assures that AdLeaks must process only a frac-tion of the resulting traffic in order to receive disclo-sures with high probability. We describe the design of AdLeaks and evaluate its performance through analysis and experimentation.