StateSync-GKR: Design and Evaluation of a Reusable Sparse GKR Engine

Abstract

Authenticated state transitions need proof engines that conserve memory, avoid repeated setup, and preserve request semantics across parallel execution. We present StateSync-GKR, a reusable Rust sumcheck/GKR core with a sparse-Merkle frontend, and connect its design mechanisms to controlled measurements. Sparse layer reduction and derived wiring reduce prover ownership and repeated verification work. Cube/affine fusion and parallel path constraints keep the circuit schedule and proof-size growth compact. Reusable preparation and indexed parallel jobs amortize setup while maintaining independent results. Three-state records, strict original-request decoding, and separate core/model interfaces expose the application and assurance boundaries. With circuit, field, transcript and prover driver held fixed, sparse reduction lowers additional requested allocation 3,242-fold and peak process resident memory 89.46-fold relative to StateSync-GKR's test-only dense reference for a two-layer mixed circuit of width 4096. Direct depth-24 fresh/prepared measurements show 3.46-4.45-fold lower per-request proving-path latency. CPU and full-proof delivery studies distinguish useful parallel work from queueing and return-path costs, retaining all outcomes and latency budgets. The evaluation supports larger circuits within finite RAM, lower repeated-request cost, and explicit deployment choices for this artifact. It preserves the cryptographic claim boundary of the existing construction.