Activists and whistleblowers often handle sensitive documents that can incriminate both the exposed parties and themselves for acquiring or distributing the material. To move forward with their revelations, they must ensure they leave no identifiable trail. Enter Dangerzone, an open-source tool that sanitizes suspicious documents and removes incriminating metadata in the process.

This talk covers metadata removal: concrete examples of how metadata has been used to de-anonymize authors and distributors, the limitations of current tools, and the challenges posed by adversaries who can apply advanced watermarking and tracing techniques to documents.