Hardening Encrypted Patient Names Against Cryptographic Attacks Using Cellular Automata
Rainer Schnell, Christian Borgs · 2018
Linking information across different databases enables new research in the medical sciences. Recent EU privacy regulations recommend encrypting personal identifiers used for linking. In this contribution, a new method for hardening such a privacy-preserving record linkage technique (PPRL) against attacks is presented. The new hardening method prevents re-identifications and cryptographic attacks while still delivering acceptable linkage quality. Using real-world mortality data, we compare clear-text and several current PPRL methods with our newly proposed method. While all PPRL methods will have to balance security and quality, the use of a cellular automata transformation to protect against attacks will decrease the linkage quality only slightly, while preventing all currently known methods of decrypting Bloom filter-based private linkage keys.