A Comprehensive Analysis on the Leakage of Fuzzy Matchers

This paper provides a comprehensive analysis of information leakage during distance evaluation, with an emphasis on threshold-based obfuscated distance (i.e., Fuzzy Matcher). Leakage can occur due to a malware infection or the use of a weakly privacy-preserving matcher, exemplified by side channel attacks or partially obfuscated designs. We provide an exhaustive catalog of information leakage scenarios as well as their impacts on the security concerning data privacy. Each of the scenarios leads to generic attacks whose impacts are expressed in terms of computational costs, hence allowing the establishment of upper bounds on the security level.