On the Limitations of Computational Fuzzy Extractors

Abstract

We present a negative result of fuzzy extractors with computational security. Specifically, we show that, under a computational condition, a computational fuzzy extractor implies the existence of an information-theoretic fuzzy extractor with slightly weaker parameters. Our result implies that to circumvent the limitations of information-theoretic fuzzy extractors, we need to employ computational fuzzy extractors that are not invertible by non-lossy functions.