Proof Networks: Connecting Coprocessors to Blockchains

What is a proof network?

A proof network is an off-chain infrastructure layer that coordinates the generation, verification, and delivery of zero-knowledge proofs across blockchain applications. It serves as the connective tissue between ZK coprocessors and the blockchain layer, ensuring that proofs generated off-chain can be efficiently validated on-chain in a scalable and decentralized manner.

ZK coprocessors are capable of producing cryptographic proofs for arbitrary computation. However, these systems need a way to route the proofs to the right on-chain environments, manage data dependencies, and ensure that proofs are generated on time and with integrity. Proof networks address these needs by acting as decentralized or semi-decentralized layers that manage provers, verifiers, and related orchestration components.

Instead of having each smart contract, rollup, or application set up its own isolated prover infrastructure, proof networks allow multiple entities to tap into a shared ecosystem of provers. This reduces duplication, lowers costs, and creates a more modular and composable ecosystem for zero-knowledge applications.

How they bridge coprocessors and smart contracts

The role of a proof network is to take a proof generated by a ZK coprocessor and deliver it to an on-chain verifier in a format that can be consumed by smart contracts. This process involves several steps, often abstracted from the end user.

First, the user or contract submits a request to a ZK coprocessor via a frontend or API. The coprocessor executes the required logic and generates a proof. Instead of posting the proof directly on-chain, it is sent to a proof network coordinator, which ensures that the proof is valid, associated with the correct computation, and not duplicated.

Once validated, the proof network either posts the proof on-chain itself or returns it to the user or relayer, who then includes it in a transaction. The smart contract receives the proof and verifies it using a preloaded verification key. If the verification passes, the contract continues its logic based on the trusted result.

This architecture makes ZK infrastructure scalable and composable. Instead of hardcoding specific circuits or proof systems into each smart contract, developers can rely on a proof network to serve as the middleware layer, connecting off-chain computation to on-chain state transitions.

Key parts: Provers, verifiers, relayers, coordinators

A typical proof network includes several functional roles. Provers are responsible for generating the cryptographic proofs. They run the computation defined by the application and use cryptographic libraries to create a proof that the computation was done correctly. Provers may be specialized nodes, GPU workers, or trusted execution environments, depending on the network’s design.

Verifiers are on-chain smart contracts that check the validity of submitted proofs. They are lightweight, deterministic, and secure. Once a proof passes verification, the associated computation is accepted as valid by the blockchain.

Relayers are off-chain actors that handle communication between the prover infrastructure and the blockchain. They submit proofs to the appropriate contract, include necessary metadata, and ensure timely delivery. In some networks, relayers are optional; in others, they are incentivized participants.

Coordinators manage the matching of requests to provers. They receive user queries or computation requests and assign them to available provers. Coordinators can also aggregate results, deduplicate identical computations, and provide availability guarantees. In decentralized networks, this coordination layer can be implemented through staking and slashing mechanisms to ensure integrity.

The separation of these roles allows for flexible architecture. A single actor can perform multiple roles in smaller networks, or roles can be split across many participants in a larger system. This modularity is key to scaling proof systems across different blockchains and use cases.

Real-world examples: Succinct, ZeroGravity, Lagrange

Several projects are building proof networks in production environments. Succinct’s Prover Network allows developers to generate ZK proofs on demand and push them to any EVM-compatible chain. It supports decentralized proving and aims to make any on-chain application verifiable with succinct proofs. Succinct has also piloted its infrastructure on World Chain, a rollup experiment by Tools for Humanity.

ZeroGravity is building a fully decentralized proving layer that supports multiple proving backends. It focuses on interoperability and aims to connect ZK coprocessors with Ethereum, rollups, and modular blockchains like Celestia. By abstracting the proof generation and verification stack, it allows applications to plug into a unified ZK layer.

Lagrange Network specializes in verifiable data availability and state queries. It enables applications to request proof-backed answers to cross-chain queries, such as verifying token balances or NFT ownership on other chains. Lagrange uses a modular approach, allowing developers to choose proof systems and data sources according to their application’s needs.

Each of these networks tackles a different layer of the problem. Some focus on compute, others on data access, and others on protocol-level infrastructure. Together, they are shaping an ecosystem in which zero-knowledge computation can become a standardized, reusable layer in blockchain design.

Native vs. Modular verification

There are two main models for how proof networks interact with blockchains: native verification and modular verification.

Native verification means that the blockchain itself, often at the protocol level, supports verification of zero-knowledge proofs. This is the case with Ethereum, which includes precompiled contracts for verifying Groth16 and PLONK proofs. Native support ensures faster verification and lower gas costs, but it requires standardization and limits the types of proofs that can be used.

Modular verification takes a different approach. It treats proof networks as external services that can connect to any chain using contracts or bridges. The on-chain verifier contract might be deployed by the application itself, and the proof format is defined off-chain. This model is more flexible, allowing developers to use new proving systems and custom logic. However, it comes with higher costs and complexity.

Choosing between native and modular verification depends on the needs of the application. Native verification is suitable for high-volume applications with predictable proof formats. Modular verification is better for research, custom logic, or rapidly evolving systems. Proof networks are increasingly designed to support both models, providing fallback paths and compatibility layers.

As ZK technology continues to evolve, proof networks are emerging as the key infrastructure for scalable, trustless computation. They enable developers to build powerful off-chain systems and connect them securely to blockchain environments. In doing so, they turn zero-knowledge proofs from a cryptographic concept into a production-ready technology stack.