CIC Visitor Seminar – September 2017
Professor Rainer Schnell presents
Recent Developments in Bloom Filter-based Methods for Privacy Preserving Record Linkage
Combining data of the same unit using multiple databases is becoming increasingly popular in official statistics, the social sciences, medical research, criminology and other quantitative research fields. If the data entities are natural persons, linking different data sources is often restricted to encrypted personal identifiers when no unique personal linkage key (PID) is available. In this setting, techniques of the very active research field of Privacy Preserving Record Linkage (PPRL) have to be used.
Recently, Bloom Filters for PPRL applications have become increasingly popular, due to their similarity-preserving properties which enable the use of similarity threshold-based linkage techniques. Since these properties could lead to security vulnerabilities, the cryptographic properties of Bloom Filters are of special interest.
Previous research has shown that the straight application of Bloom Filters has a non-zero re-identification risk. Some recently developed techniques for attacking Bloom Filter encodings will be described shortly. We will present new results on new methods to make attacks on Bloom Filters increasingly difficult. These computationally simple algorithms modify the identifiers by different cryptographic diffusion techniques, among these are applications of Cellular Automata and Markov Chains. The presentation will demonstrate these new algorithms and show their performance concerning precision and recall in large databases.
Rainer Schnell holds the chair for Research Methodology in the Social Sciences at the University of Duisburg-Essen, Germany. He is former Director of the Centre for Comparative Surveys at City University London and graduated with a postdoctoral degree in Research Methodology at the University of Mannheim in 1996. His research focuses on non-sampling errors, applied sampling, census operations and privacy preserving record linkage. Professor Schnell founded the German Record Linkage Centre and was founding editor of the journal “Survey Research Methods”. He is the author of books on Statistical Graphics (1994), Nonresponse (1997), Survey Methodology (2012), Research Methodology (10th ed. 2013) and of more than 30 papers on Privacy Preserving Record Linkage.
The presentation will be followed by afternoon tea and networking.