Further information

Background

Storing sensitive data in compliance with data protection regulations poses a particular challenge when it has to be stored on publicly accessible or externally operated servers. One promising requirement here is the principle of zero-knowledge storage: data should be stored in encrypted form so that even the server operator cannot access the plain text data. Cryptographic methods, in particular asymmetric and hybrid approaches that combine symmetric and asymmetric encryption, offer different solutions for this, each of which involves different compromises in terms of security, performance and practicability.

Task definition

The target of the work is to systematically analyze relevant cryptographic approaches for server operator-independent data storage and to evaluate them on the basis of suitable criteria. The requirements for such a system must first be worked out and an evaluation framework developed. Possible focal points include

• Systematic review of relevant cryptographic procedures (asymmetric vs. hybrid) and the current state of research
• Development of a list of criteria for evaluating the approaches in terms of security, data protection compliance (in particular GDPR), performance and feasibility
• Comparative evaluation of the identified approaches based on the developed framework
• Prototypical implementation of a selected approach as a proof of concept

Own ideas and focal points can be introduced in consultation.