Transparency Enhancing Tools (TETs): An Overview

As the amount of users' information collected and exchanged on the Internet is growing, so are, consequently, the users' concerns that their privacy might be violated. Some studies have shown that a large number of users avoid engaging in online services due to privacy concerns. It has been suggested that increased transparency of privacy related mechanisms may promote users' trust. This paper reviews the relationship between users' privacy concerns, transparency enhancing and privacy enhancing mechanisms on the one hand, and users' trust on the other, based on the existing literature. Our literature review demonstrates that previous studies have produced inconsistent results, implying this relationship should be re-examined in future work. Impact of higher transparency on users' trust has been insufficiently studied. Current research seems to suggest that the increase of the understanding of privacy issues increases importance of privacy for trust. Use of privacy enhancing mechanisms by service provider also seems to promote the trust, but this may only hold when these mechanisms are understood by the user. A need for tools that would provide users with this kind of knowledge has also been repeatedly recognized. Additionally, this paper provides an overview and description of the currently available transparency enhancing tools. To the best of our knowledge, no such overview has been available to this end. We demonstrate that the majority of tools promote awareness. Most of them attempt to provide a better understanding of privacy policies, or provide insight in the third party tracking behavior. Two tools have been identified that provide some insight in the collected user's data. No tool providing specific information on, or access to, processing logic has been identified.