Concurrent zero-knowledge with timing, revisited

摘要: Following Dwork, Naor, and Sahai (30th STOC, 1998), we consider concurrent executions of protocols in a semi-synchronized network. Specifically, assume that each party holds local clock such bounds on the relative rates these clocks as well message-delivery time are a-priori known, employ time-driven operations (i.e., time-out in-coming messages delay out-going messages). We show constant-round zero-knowledge proof for ${\cal NP}$ Goldreich Kahan (Jour. Crypto., 1996) preserves its security when polynomially-many independent copies executed concurrently under above timing model. We stress our main result refers to interactive proofs, whereas results Dwork et. al. either arguments or weak notion (called epsilon-knowledge) proofs. Our analysis identifies two extreme schedulings model: first is case parallel execution copies, second only small constant) number simultaneously active at any bounded simultaneity). Dealing with cases interest, general (regarding model) obtained by combining treatments.