PostGuard (2020-)

PostGuard is an add-on for Outlook and Thunderbird that offers free and easy-to-use end-to-end encryption for emails and a website to share encrypted files effortlessly. PostGuard is based on identity-based encryption and utilizes the IRMA app to ensure only the intended recipient can decrypt a file. I have worked on PostGuard as one of the project leads and as a supervisor of the involved PhD students. PostGuard can be found online at The code is on GitHub: We also published a paper about the concept.

Paper reference: Botros, L., Brandon, M., Jacobs, B., Ostkamp, D., Schraffenberger, H.K., & Venema, M. (2023). Postguard: Towards easy and secure email communication. In CHI Extended Abstracts (p. 232:1–232:6.). ACM.