Verifiable evaluations of machine learning models using zkSNARKs
Tobin South, Alexander Camuto, Shrey Jain, Shayla Nguyen, Robert Mahari, Christian Paquin, Jason Morton, Alex 'Sandy' Pentland
TL;DR
The paper addresses the problem of verifying performance claims for closed-weight ML systems, where end users cannot reproducibly confirm benchmarks. It introduces a verifiable evaluation framework based on zkSNARKs that proves inference over datasets without revealing model weights, using a four-step ONNX-to-proof workflow and a 'predict, then prove' strategy to separate inference from proof generation. The contributions include a generalizable, end-to-end attestation framework, a flexible proving system (mapping ONNX to proof circuits via Halo2 and the ezkl toolkit), and a cost-aware discussion with demonstrations across diverse architectures, along with privacy-preserving aggregation and challenge-based audits. This approach enables transparent, auditable benchmarking and model integrity in high-stakes or private-weight contexts, while maintaining weight confidentiality and scalability through modular proofs and attestations.
Abstract
In a world of increasing closed-source commercial machine learning models, model evaluations from developers must be taken at face value. These benchmark results-whether over task accuracy, bias evaluations, or safety checks-are traditionally impossible to verify by a model end-user without the costly or impossible process of re-performing the benchmark on black-box model outputs. This work presents a method of verifiable model evaluation using model inference through zkSNARKs. The resulting zero-knowledge computational proofs of model outputs over datasets can be packaged into verifiable evaluation attestations showing that models with fixed private weights achieve stated performance or fairness metrics over public inputs. We present a flexible proving system that enables verifiable attestations to be performed on any standard neural network model with varying compute requirements. For the first time, we demonstrate this across a sample of real-world models and highlight key challenges and design solutions. This presents a new transparency paradigm in the verifiable evaluation of private models.
