International Association for Cryptologic Research (IACR)
Abstract
In this paper we resolve the question of whether or not constrained pseudorandom functions (CPRFs) can be built directly from pseudorandom synthesizers. In particular, we demonstrate that the generic PRF construction from pseudorandom synthesizers due to Naor and Reingold can be used to construct CPRFs with bit-fixed predicates using the direct-line\u27\u27 approach. We further introduce a property of CPRFs that may be of independent interest