During April 2021, Protocol Labs engaged NCC Group’s Cryptography Services team to conduct a cryptography and implementation review of the Groth16 proof aggregation functionality in the bellperson and two other related GitHub repositories. This code utilizes inner product arguments to efficiently aggregate existing Groth16 proofs while re-using existing powers of tau ceremony transcripts. Full source code access was provided with support over Slack. The project concluded with a brief retest several weeks after the initial review.
The Public Report for this review may be downloaded below: