Privacy Protection for Social Network Services

outline Privacy issues with online social networks (or social network services) Research challenges Two sample approaches Privacy wizard Privacy score Summary

Rapid growth of SNS - Facebook

situations SNS data are profitable to SNS providers SNS utilities are valuable to users, SNS providers, and App Develops All SN data are sensitive Different users may have different privacy requirements.  There are many profile items, each of which may require different protection levels.  Many users are not aware of privacy risk Contents might be generated collaboratively. 

Research issues Outsourcing SN data (discussed) Users’ privacy setting Privacy preserving use of SN data (SNS providers/app developers) Tradeoff between privacy and utility

Focus on two problems Helping user set appropriate privacy levels for many profile items Evaluate the privacy risk

Automatic Privacy Setting Problems Average users don’t know how to express their privacy preferences. What does it mean for specific privacy settings. Solutions Design automatic tools to do this task. Challenges Solicit input from user – as easy and straightforward as possible. Adapt to changes.

Privacy Wizard Using machine learning algorithms to train a privacy preference selector for profile items. Training data: existing users’ privacy settings, biographical information Input: the user’s bio info, output: the setting for a specific item Assumption: people with similar bio info may have similar privacy preference.

Observations Such models might exist Accuracy of the models Friends may share similar opinions on privacy setting Access control is defined on groups? Accuracy of the models The amount of training data Properly group users

The privacy wizard

Comments on Privacy Wizard Strengths: One of the first attempts to answer the question of automatic privacy settings. Model can work for controlling private profile items. problems Difficult on dynamic contents, such as photos and wall posts. Assumptions might not hold – privacy setting is a very personalized choice