Efficient and Practical Privacy-Preserving Kidney Exchange Protocol

Bachelor Thesis

Published in BMC Medical Informatics and Decision Making'22


Given the extremely personal and sensitive information that are involved in health care and medical analysis, applications in this field exhibit high security and privacy requirements that go beyond compliance to legal regulations like the GDPR [1] and HIPAA [2]. These requirements can prohibit the usage of data from different sources, e.g., several hospitals, although more data often improves the quality of analytics. For example, for organ donations, it is necessary to find pairs of donors and patients. While typically relatives offer to be a donor for their relatives in need, they may not be compatible. One possible option is to combine several incompatible pairs of donors and patients in a cyclic network until everyone gets a compatible match [3]. However, doing such a matching manually is impractical and therefore calls for an automated system which must ensure correctness and guarantee to protect all sensitive information. Previous work [3] only provides an inefficient solution that is not scalable to a large number of patients and donors.


The goal of this work is to investigate the real-world requirements for an application that supports the matching of compatible organ donors and patients in Germany/Europe/US. This should also take legal regulations into account.

The findings shall be realised by designing and implementing an efficient and practical privacy-preserving protocol using suitable cryptographic means. The implementation then has to be benchmarked with respect to computation and communication and compared to previous work [3].


  • Good programming skills in C/C++
  • At least basic knowledge of cryptography
  • High motivation + ability to work independently
  • Knowledge of the English language, Git, LaTeX, etc. goes without saying




Timm Birka, Kay Hamacher, Tobias Kussel, Helen Möllering, and Thomas Schneider: SPIKE: Secure and Private Investigation of the Kidney Exchange problem (opens in new tab). In BMC Medical Informatics and Decision Making, 2022.