Skip to main content.

Oblivion: Mitigating Privacy Leaks by Controlling the Discoverability of Online Information

Muhammad Rizwan Asghar, Michael Backes, Fabian Bendun, Peter Druschel, Ninja Marnau, Milivoj Simeonovski


Search engines are the prevalently used tools to collect information about individuals in the Internet. Search results typically comprise a variety of sources that contain personal information – either intentionally released by the person herself or unintentionally leaked or unnoticedly published by third parties, often with detrimental effects on the individual’s privacy. To grant individuals the ability to regain control over their disseminated personal information, the European Court of Justice recently ruled that EU citizens have a right to be forgotten in the sense that indexing systems, such as Google, must offer them technical means to request removal of links from search results that point to sources violating their data protection rights. As of now, these technical means consist of a web form that requires a user to manually identify all relevant links herself upfront and to insert them into the web form, followed by a manual evaluation by employees of the indexing system to assess if the request to remove those links is eligible and lawful. In this work, we propose a universal framework Oblivion to support the automation of the right to be forgotten in a scalable, provable and privacy-preserving manner. First, Oblivion enables a user to automatically find and tag her disseminated personal information using Natural Language Processing (NLP) techniques and file a request in a privacy preserving manner. Second, Oblivion provides indexing systems with an automated and provable eligibility mechanism, asserting that the author of a request is indeed affected by an online resource. The automated eligibility proof of Oblivion ensures censorship-resistance so that only legitimately affected individuals can request the removal of corresponding links from search results. We have conducted comprehensive evaluations of Oblivion, showing that the framework is capable of handling 278 removal requests per second on a standard notebook (2.5 GHz dual core), and is hence suitable for large-scale deployment.

Where to get the security analysis

The complete formalization in the applied π-calculus can be downloaded here.

Scientific Publication

Attention in the media

Motherboard   22. June. 2015 (External link)
Daily Mail   26. June. 2015 (External link)
NZ Herald   05. August. 2015 (External link)
3 News   10. August. 2015 (External link)


In case of questions please contact:

 Muhammad Rizwan Asghar [r.asghar (at) auckland (dot) ac (dot) nz]
 Milivoj Simeonovski [simeonovski (at) cs (dot) uni-saarland (dot) de]
Data Privacy Policy Impressum