Encoding and Comparing Sensitive Values

Abstract

Over the past nearly two decades researchers from different domains, including statistics, the social and health sciences, and computer science, have developed a variety of techniques to link sensitive databases in a privacy-preserving way. Many of these techniques have so far not been used in practical applications for a variety of reasons that range from security weaknesses or limitations in linkage capabilities to prohibitive computational requirements. We begin this chapter with a taxonomy that has been developed to categorise techniques for encoding and comparing sensitive databases based on different dimensions ranging from privacy and technical to practical aspects, and we provide a general discussion of the different generations of techniques that have been developed. We then give brief overviews of specific techniques, including those based on phonetic encoding, hashing, public reference values, embedding into multidimensional spaces, and secure multiparty computation. We end the chapter with a discussion on the suitability of these types of techniques for different linkage scenarios.