The PSOTI project addressed privacy concerns with Internet services such as email, forms, and messaging. These services often require data to be stored in the clear on servers managed by a single service provider. The data is then processed further, which requires the data to be unencrypted, infringing on the privacy of the data owner, namely the user of the service. Furthermore, having a single service provider introduces a single point of failure in the system where a successful attack on the service provider can compromise the data of many users.
Privacy has always been an essential human right, but it is often overlooked in today's convenient Internet services, which have become an essential part of our lives. Some steps have been taken to legally limit the service providers' power over users' data, such as the EU General Data Protection Regulation (GDPR). However, providing privacy-preserving services while providing a rich set of functionalities is very challenging.
The primary objective of the PSOTI project was to showcase that certain Internet services can be realized while still preserving privacy. For this, we substantially improved protocols and built frameworks for Secure Multi-Party Computation (MPC), allowing the secure processing of data under encryption. Moreover, we proposed MPC-based solutions and built prototype implementations that allow users to privately send, store, or even process data using multiple service providers.
In conclusion, we have shown that we do not require a single service provider to have plaintext access to the data, but multiple service providers can jointly and privately provide functionalities.
