Sara Ramezanian defends her PhD thesis on Privacy-Preserving Protocols for Protected Networking

On Friday the 10th of June 2022, M.Sc. Sara Ramezanian defends her doctoral thesis on Privacy-Preserving Protocols for Protected Networking. The thesis is related to research done in the Department of Computer Science and in the Secure Systems group.

M.Sc. Sara Ramezanian defends her doctoral thesis Privacy-Preserving Protocols for Protected Networking on Friday the 10th of June 2022 at 12 o'clock in the University of Helsinki Exactum building, Auditorium CK112 (Pietari Kalmin katu 5, ground floor). Her opponent is Professor Panos Papadimitratos (KTH Royal Institute of Technology, Sweden) and custos Professor Valtteri Niemi (University of Helsinki). The defence will be held in English.

The thesis of Sara Ramezanian is a part of research done in the Department of Computer Science and in the Secure Systems group at the University of Helsinki. Her supervisors have been Professor Valtteri Niemi and Senior Researcher Tommi Meskanen (University of Helsinki).

Privacy-Preserving Protocols for Protected Networking

Digital technologies have become an essential part of our lives. In many parts of the world, activities such as socializing, providing health care, leisure and education are entirely or partially relying on the internet. Moreover, the COVID-19 world pandemic has also contributed significantly to our dependency on the on-line world.

While the advancement of the internet brings many advantages, there are also disadvantages such as potential loss of privacy and security. While the users enjoy surfing on the web, service providers may collect a variety of information about their users, such as the users’ location, gender, and religion. Moreover, the attackers may try to violate the users’ security, for example, by infecting the users’ devices with malware.

In this PhD dissertation, to provide means to protect networking we propose several privacy-preserving protocols. Our protocols empower internet users to get a variety of services, while at the same time ensuring users’ privacy and security in the digital world. In other words, we design our protocols such that the users only share the amount of information with the service providers that is absolutely necessary to gain the service. Moreover, our protocols only add minimal additional time and communication costs, while leveraging cryptographic schemes to ensure users’ privacy and security.

The dissertation contains two main themes of protocols: privacy-preserving set operations and privacy-preserving graph queries. These protocols can be applied to a variety of application areas. We delve deeper into three application areas: privacy-preserving technologies for malware protection, protection of remote access, and protecting minors.

Avail­ab­il­ity of the dis­ser­ta­tion

An electronic version of the doctoral dissertation is available on the e-thesis site of the University of Helsinki at

Printed copies will be available on request from Sara Ramezanian: