Perfect Non-interactive Zero Knowledge for NP

Non-interactive zero-knowledge (NIZK) proof systems are fundamental cryptographic primitives used in many constructions, including CCA2-secure cryptosystems, digital signatures, and various cryptographic protocols. What makes them especially attractive, is that they work equally well in a concurrent setting, which is notoriously hard for interactive zero-knowledge protocols. However, while for interactive zeroknowledge we know how to construct statistical zero-knowledge argument systems for all NP languages, for non-interactive zero-knowledge, this problem remained open since the inception of NIZK in the late 1980's. Here we resolve two problems regarding NIZK:

• Type: Conference
• Year: 2006
• Where: EUROCRYPT
• Authors: Jens Groth, Rafail Ostrovsky, Amit Sahai
• Keywords: Cryptology, EUROCRYPT 2006, Interactive Zero-knowledge Protocols, Non-interactive Zero-knowledge, NP Language