Publication Date

Spring 2023

Degree Type

Master's Project

Degree Name

Master of Science (MS)


Computer Science

First Advisor

Chris Pollett

Second Advisor

Nada Attar

Third Advisor

Namrata Bilurkar


moderation, differential privacy, secret sharing


Yioop is an open-source web portal that serves as a search engine and a discussion board, enabling users to create, join, and share content within groups. Data security is a critical concern for Yioop, as it involves storing and accessing user-generated data and generating statistical data. Yioop has an existing security mechanism in place, but continuous enhancements are needed to protect against potential vulnerabilities and cyber threats.

This project aims to strengthen the security of Yioop by implementing additional security measures that build upon the existing security mechanism. To prevent statistical attacks, this project extends differential privacy to mask the number of users in groups. Furthermore, a flag feature is added to allow users to flag posts that they find offensive, which is reviewed by a newly added moderator group. Secret sharing is employed to further fortify the encryption keys, ensuring that only authorized users with the required shares can potentially use the key. These security measures have been rigorously tested and evaluated to ensure that they effectively contribute to the overall security of Yioop, enabling users to enjoy secure interactions and content sharing within the portal while preserving their privacy and confidentiality.

This report provides an in-depth overview of these security measures, their implementation, testing procedures, and their impact on Yioop’s overall security. The success of this project will contribute to a more secure environment for Yioop users, preserving user privacy and confidentiality while promoting secure interactions and content sharing within the portal.