Batch Groth-Sahai
O. Blazy, G. Fuchsbauer, M. Izabachène, A. Jambert, H. Sibert, and D. Vergnaud.
Abstract:

In 2008, Groth and Sahai proposed a general methodology for constructing non-interactive zero-knowledge (and witness-indistinguishable) proofs in bilinear groups. While avoiding expensive NP-reductions, these proof systems are still inefficient due to the number of pairing computations required for verification. We apply recent techniques of batch verification to the Groth-Sahai proof systems and succeed to improve significantly the complexity of proof verification. We give explicit batch-verification formulas for generic Groth-Sahai equations (whose cost is less than a tenth of the original) as well as for specific popular protocols relying on their methodology (namely Groth's group signatures and the P-signatures by Belenkiy, Chase, Kohlweiss and Lysyanskaya).