The Cookieless Monster: Exploring the Ecosystem of Web-Based Device Fingerprinting | Nikiforakis, Kapravelos, Joosens, Kruegel, Piessens, Vigna

Nick Nikiforakis, Alexandros Kapravelos, Wouter Joosens, Christopher Kruegel, Frank Piessens, Giovanni Vigna; The Cookieless Monster: Exploring the Ecosystem of Web-Based Device Fingerprinting; In Proceedings of the IEEE Symposium on Security & Privacy (SP); 2013; pages 541-555 (15 pages); landing.


The web has become an essential part of our society and is currently the main medium of information delivery. Billions of users browse the web on a daily basis, and there are single websites that have reached over one billion user accounts. In this environment, the ability to track users and their online habits can be very lucrative for advertising companies, yet very intrusive for the privacy of users.

In this paper, we examine how web-based device fingerprinting currently works on the Internet. By analyzing the code of three popular browser-fingerprinting code providers, we reveal the techniques that allow websites to track users without the need of client-side identifiers. Among these techniques, we show how current commercial fingerprinting approaches use questionable practices, such as the circumvention of HTTP proxies to discover a user’s real IP address and the installation of intrusive browser plugins.

At the same time, we show how fragile the browser ecosystem is against fingerprinting through the use of novel browser-identifying techniques. With so many different vendors involved in browser development, we demonstrate how one can use diversions in the browsers’ implementation to distinguish successfully not only the browser-family, but also specific major and minor versions. Browser extensions that help users spoof the user-agent of their browsers are also evaluated. We show that current commercial approaches can bypass the extensions, and, in addition, take advantage of their shortcomings by using them as additional fingerprinting features.


  • BlueCava
  • iovation
  • ThreatMetrix
  • Ghostery
  • Panopticlick


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Web Privacy and Transparency Conference

Web Privacy and Transparency Conference; Center for Information Technology Policy at Princeton; 2014-10-24.

tl;dr => a 1-day session


PriVaricator: Deceiving Fingerprinters with Little White Lies | Nikiforakis, Joosen, Livshits


Nick Nikiforakis, Wouter Joosen, Benjamin Livshits; PriVaricator: Deceiving Fingerprinters with Little White Lies; Technical Report MSR-TR-2014-26; Microsoft;
2014-02-28; 14 pages; landing.


This paper proposes a solution to the problem of browser-based fingerprinting. An important observation is that making fingerprints non-deterministic also makes them hard to link across subsequent web site visits. Our key insight is that when it comes to web tracking, the real problem with fingerprinting is not uniqueness of a fingerprint, it is linkability, i.e. the ability to connect the same fingerprint across multiple visits. In PriVaricator we use the power of randomization to “break” linkability by exploring a space of parameterized randomization policies. We evaluate our techniques in terms of being able to prevent fingerprinting and also in terms of not breaking existing (benign) sites. The best of our randomization policies renders all the fingerprinters we tested ineffective, while causing minimal damage on a set of 1,000 Alexa sites on which we tested, with no noticeable performance overhead.


Ad groups prepare for “cookieless” future, develop opt-out tool for alternative tracking | SFGate

James Temple; Ad groups prepare for “cookieless” future, develop opt-out tool for alternative tracking; In SFGate; 2013-10-04.

Gunes Acar, Marc Juarez, Nick Nikiforakis, Claudia Diaz, Seda Gürses, Frank Piessens, Bart Preneel; FPDetective: Dusting the Web for Fingerprinters; In Proceedings of Computer and Communications Security (CCS); 2013-11-04; 13 pages.