Towards a Privacy-Enhanced Social Networking Site

TLDR: This paper highlights some privacy issues raised by the growing development of SNS and identifies clearly three privacy risks, and introduces the concept of a Privacy-enhanced Social Networking Site (PSNS), and describes Privacy Watch, the first implementation of a PSNS.

Abstract: Social Networking Sites (SNS), such as Facebook and LinkedIn, have become the established place for keeping contact with old friends and meeting new acquaintances. As a result, a user leaves a big trail of personal information about him and his friends on the SNS, sometimes even without being aware of it. This information can lead to privacy drifts such as damaging his reputation and credibility, security risks (for instance identity theft) and profiling risks. In this paper, we first highlight some privacy issues raised by the growing development of SNS and identify clearly three privacy risks. While it may seem a priori that privacy and SNS are two antagonist concepts, we also identified some privacy criteria that SNS could fulfill in order to be more respectful of the privacy of their users. Finally, we introduce the concept of a Privacy-enhanced Social Networking Site (PSNS) and we describe Privacy Watch, our first implementation of a PSNS.

Figures

Figure 5.5: Privacy Advisor

Figure 6.3: Privacy Wizard.

Figure 4.3: Which types of persons do you have in your friend lists?

Figure 4.1: Information on SNS profiles.

Figure 5.9: New User Registration.

Figure 5.8: Implementation of Privacy Watch.

Full text

Université de Montréal
Towards a Privacy-enhanced Social Networking Site
par
Ai Thanh Ho
Département d’informatique et de recherche opérationnelle
Faculté des arts et des sciences
Thèse présentée à la Faculté des arts et des sciences
en vue de l’obtention du grade de Philosophiæ Doctor (Ph.D.)
en informatique
Avril, 2012
c
 Ai Thanh Ho, 2012.

Université de Montréal
Faculté des arts et des sciences
Cette thèse intitulée:
Towards a Privacy-enhanced Social Networking Site
présentée par:
Ai Thanh Ho
a été évaluée par un jury composé des personnes suivantes:
Guy Lapalme, président-rapporteur
Esma Aïmeur, directrice de recherche
Sébastien Gambs, codirecteur
Louis Salvail, membre du jury
Julita Vassileva, examinateur externe
André-A Lafrance, représentant du doyen de la FAS
Thèse acceptée le: . . . . . . . . . . . . . . . . . . . . . . . . . .

RÉSUMÉ
L’avénement des réseaux sociaux, tel que Facebook, MySpace et LinkedIn, a fourni une
plateforme permettant aux individus de rester facilement connectés avec leurs amis, leurs
familles ou encore leurs collègues tout en les encourageant activement à partager leurs
données personnelles à travers le réseau. Avec la richesse des activités disponibles sur
un réseau social, la quantité et la variété des informations personnelles partagées sont
considérables. De plus, de part leur nature numérique, ces informations peuvent être
facilement copiées, modifiées ou divulguées sans le consentement explicite de leur pro-
priétaire. Ainsi, l’information personnelle révélée par les réseaux sociaux peut affecter
de manière concrète la vie de leurs utilisateurs avec des risques pour leur vie privée allant
d’un simple embarras à la ruine complète de leur réputation, en passant par l’usurpation
d’identité. Malheureusement, la plupart des utilisateurs ne sont pas conscients de ces
risques et les outils mis en place par les réseaux sociaux actuels ne sont pas suffisants
pour protéger efficacement la vie privée de leurs utilisateurs. En outre, même si un utili-
sateur peut contrôler l’accès à son propre profil, il ne peut pas contrôler ce que les autres
révèlent à son sujet. En effet, les “amis” d’un utilisateur sur un réseau social peuvent
parfois révéler plus d’information à son propos que celui-ci ne le souhaiterait.
Le respect de la vie privée est un droit fondamental pour chaque individu. Nous pré-
sentons dans cette thèse une approche qui vise à accroître la prise de conscience des
utilisateurs des risques par rapport à leur vie privée et à maintenir la souveraineté sur
leurs données lorsqu’ils utilisent un réseau social. La première contribution de cette thèse
réside dans la classification des risques multiples ainsi que les atteintes à la vie privée
des utilisateurs d’un réseau social. Nous introduisons ensuite un cadre formel pour le
respect de la vie privée dans les réseaux sociaux ainsi que le concept de politique de
vie privée (UPP). Celle-ci définie par l’utilisateur offre une manière simple et flexible
de spécifier et communiquer leur attentes en terme de respect de la vie privée à d’autres
utilisateurs, tiers parties ainsi qu’au fournisseur du réseau social. Par ailleurs, nous dé-
finissons une taxonomie (possiblement non-exhaustive) des critères qu’un réseau social
peut intégrer dans sa conception pour améliorer le respect de la vie privée. En introdui-

iv
sant le concept de réseau social respectueux de la vie privée (PSNS), nous proposons
Privacy Watch, un réseau social respectueux de la vie privée qui combine les concepts
de provenance et d’imputabilité afin d’aider les utilisateurs à maintenir la souveraineté
sur leurs données personnelles. Finalement, nous décrivons et comparons les différentes
propositions de réseaux sociaux respectueux de la vie privée qui ont émergé récemment.
Nous classifions aussi ces différentes approches au regard des critères de respect de la
vie privée introduits dans cette thèse.
Mots clés: Vie privée, réseaux sociaux, imputabilité, filigrane, cryptage, contrôle
d’accès.

ABSTRACT
The rise of Social Networking Sites (SNS), such as Facebook, Myspace, and LinkedIn
has provided a platform for individuals to easily stay in touch with friends, family and
colleagues and actively encourage their users to share personal information. With the
wealth of activities available on SNS, the amount and variety of personal information
shared is considerable and diverse. Additionally, due to its digital nature, this informa-
tion can be easily copied, modified and disclosed without the explicit consent of their
owner. Personal information disclosed from SNS could affect users’ life, with privacy
risks ranging from simple embarrassment to ruining their reputation, or even identity
theft. Unfortunately, many users are not fully aware of the danger of divulging their per-
sonal information and the current privacy solutions are not flexible and thorough enough
to protect user data. Furthermore, even though users of SNS can control access to their
own profile, they cannot control what others may reveal about them. Friends can some-
times be untrustworthy and disclose more information about the user than they should.
Considering that privacy is a fundamental right for every individual, in this thesis,
we present an approach that increases privacy awareness of the users and maintains
the sovereignty of their data when using SNS. The first contribution of this thesis is the
classification of multiple types of risks as well as user expectations regarding privacy in
SNS. Afterwards, we introduce the Privacy Framework for SNS and the concept of User
Privacy Policy (UPP) to offer users an easy and flexible way to specify and communicate
their privacy concerns to other users, third parties and SNS provider. Additionally, we
define a taxonomy (possibly non-exhaustive) of privacy criteria that can enhance the
user privacy if they are integrated within the design of a SNS and introduce the concept
of a Privacy-enhanced SNS (PSNS). Furthermore, we present also Privacy Watch, a
theoretical proposal of a PSNS platform that combines the concept of provenance and
accountability to help SNS users maintain sovereignty over their personal data. Finally,
we survey and compare several privacy-enhanced SNS that were recently proposed that
try to integrate some privacy features directly into the design of the system. We also
classify these different approaches with respect to the privacy criteria developed.

Frequently asked questions

Q1. What are the contributions in this paper?

The rise of Social Networking Sites ( SNS ), such as Facebook, Myspace, and LinkedIn has provided a platform for individuals to easily stay in touch with friends, family and colleagues and actively encourage their users to share personal information. Considering that privacy is a fundamental right for every individual, in this thesis, the authors present an approach that increases privacy awareness of the users and maintains the sovereignty of their data when using SNS. Afterwards, the authors introduce the Privacy Framework for SNS and the concept of User Privacy Policy ( UPP ) to offer users an easy and flexible way to specify and communicate their privacy concerns to other users, third parties and SNS provider. Additionally, the authors define a taxonomy ( possibly non-exhaustive ) of privacy criteria that can enhance the user privacy if they are integrated within the design of a SNS and introduce the concept of a Privacy-enhanced SNS ( PSNS ). Furthermore, the authors present also Privacy Watch, a theoretical proposal of a PSNS platform that combines the concept of provenance and accountability to help SNS users maintain sovereignty over their personal data. Finally, the authors survey and compare several privacy-enhanced SNS that were recently proposed that try to integrate some privacy features directly into the design of the system. Furthermore, even though users of SNS can control access to their own profile, they can not control what others may reveal about them. 

Q2. How is the Privacy Advisor able to determine the privacy level of a user?

The privacy level of a specific user is acquired through an elicitation process in the form of a question-response protocol between the Privacy Advisor and the user. 

Q3. How many people use their real name to identify themselves?

According to a 2007 survey [37], 91% of Facebook users and 62% of MySpace participants use their real name to identify themselves and 85% of the respondents either currently share or would share pictures of themselves on the aforementioned sites. 

Q4. What are the three basic rights that users expect from social network sites?

“The authors the users expect social network sites to provide us the following rights in theirTerms of Service, Privacy Policies, and implementations of their system:1. Honesty: Honor your privacy policy and terms of service. 

Q5. What are the three basic principles that SNS users should demand from their providers?

On May 2010, the Electronic Frontier Foundation has suggested three basic privacyprotective principles that SNS users should demand from their providers: the right to have informed decision-making, the right to control and the right to leave [78]. 

Q6. What is the popular way for users to share their work freely while maintaining control?

popular way for users to share their work freely while maintaining control is to publish their work under a Creative Commons license 5. 

Q7. What programs for editing pictures and photo sharing websites provide watermark functions?

Most programs for editing pictures and photo sharing websites provide watermark functions, from simple to more sophisticated ones, such as Adobe Photoshop, Visual Watermark, Watermark Studio, uMark, PicMarkr 3 and WaterMark 4 [103]. 

Q8. What was the first approach for helping users to protect their privacy in these SNS?

a first approach for helping users to protect their privacy in these SNS was in the form of privacy add-ons that were integrated within the existing systems, rather than constructing an entirely new privacy-enhanced SNS from scratch that would face the cold start issue. 

Q9. What would happen if a well-defined UPP45 was enforced?

In this case, a well-defined UPP45(if enforced) would make Alice’s name “disappear” completely from Bob’s profile and therefore becoming invisible to the eyes of other users. 

Q10. What are the main reasons why companies have turned to them?

Since the beginning of SNS, companies have turned to them to determine whether there is something about an applicant’s lifestyle that would go against the core values of their corporation. 

Q11. What is the main reason why users reduce self-representation on the platform?

Users tend to reduce self-representation on the platform when they fear that their information will be collected, stored, and used by the SNS and other third parties [51]. 

Q12. What is the way to control who can access your page?

While MySpace only allows users to limit who can access their page, Facebook lets users control who can search for them, how they can be contacted as well as what stories get published to their profile and their Friends’