Paper 2026/634

PlasmaBlind: A Private Layer 2 With Instant Client-Side Proving

Chengru Zhang, The University of Hong Kong, Ethereum Foundation

Abstract

In this technical note, we discuss a new direction in the design of privacy-preserving and scalable Layer-2 (L2) protocols by presenting a concrete construction, PlasmaBlind. To minimize the L2 users’ overhead for achieving privacy while enabling efficient creation of compact blocks, PlasmaBlind is built upon a novel architecture that leverages folding schemes’ powerful and flexible properties. On the user side, we utilize their blinding property to shield and prove transaction data without expensive succinct zero-knowledge proofs. On the aggregator side, their low accumulation cost allows efficient aggregation of user instances into a constant size proof of block validity. We further improve our proof aggregation performance by proposing an optimization technique that efficiently links two different verification tasks with shared input while eliminating the need for cumbersome proof composition of non-uniform circuits, which could be of independent interest. The practicality of PlasmaBlind is validated by our preliminary benchmarks, which demonstrate that, with consumer hardware, PlasmaBlind achieves sub-100ms proving time on the client side and sub-300ms per-transaction time on the aggregator side.