Shared Prover

A shared prover is a decentralized network or service that generates cryptographic proofs—specifically Zero-Knowledge Proofs (ZKPs) or Validity Proofs—for multiple blockchain rollups. This architecture allows individual rollups to outsource their most computationally intensive task, proof generation, to a specialized, shared infrastructure. By doing so, rollups can achieve greater scalability and cost-efficiency without each needing to maintain their own expensive proving hardware and expertise. The concept is central to modular blockchain design, where execution, settlement, and data availability are separated into distinct layers.

The core mechanism involves the shared prover network receiving execution traces (a record of transactions) from connected rollups. Provers within the network then perform the complex cryptographic computations to generate a succinct proof that verifies the correctness of those transactions. This single proof is posted back to the underlying Layer 1 (L1) blockchain, such as Ethereum, providing a secure, verifiable guarantee of the rollup's state. This model transforms proof generation from a per-rollup capital expenditure into a shared, competitive marketplace for proving services, often called a proof marketplace.

Key benefits of a shared prover architecture include economic efficiency (lower costs through resource pooling), accelerated innovation (rollup developers focus on execution environments, not proof systems), and enhanced security (decentralized proving networks reduce reliance on single operators). It also facilitates interoperability, as multiple rollups using the same proving system can more easily verify each other's states. Projects like Espresso Systems with its Espresso Sequencer and proving network, and =nil; Foundation with its Proof Market, are pioneering implementations of this concept.

From a technical perspective, shared provers often rely on advanced proof systems like zkSNARKs or zkSTARKs. The security model depends on the decentralization and cryptoeconomic incentives of the prover network to ensure liveness and honesty. Challenges include minimizing proof generation latency, managing the data availability of execution traces, and designing incentive mechanisms that prevent collusion or censorship. The evolution of shared proving is closely tied to the broader adoption of ZK-Rollups as a dominant scaling solution.

In practice, a shared prover enables a future where dozens of specialized, application-specific rollups (e.g., for gaming, DeFi, or social media) can operate securely and cheaply by all leveraging the same robust proving backbone. This moves the blockchain ecosystem toward a modular stack where critical functions like consensus, data availability, and proving are provided by optimized, reusable layers, allowing for maximum developer flexibility and user experience at the execution layer.

A shared prover is a decentralized network or service that generates validity proofs (like ZK-SNARKs or ZK-STARKs) for batches of transactions processed by separate execution layers or rollups. Instead of each rollup operating its own costly proving infrastructure, they outsource this computationally intensive task to a shared, specialized network. This model transforms proof generation from a per-chain overhead into a scalable, reusable utility, analogous to how cloud computing provides shared compute resources. The primary output is a succinct cryptographic proof that attests to the correct execution of transactions, which is then posted to a settlement layer like Ethereum for final verification and data availability.

The workflow begins when a rollup, such as a zkRollup or validium, processes a batch of transactions and produces an execution trace. This trace, representing the new state root and all state transitions, is sent to the shared prover network. Nodes within this network, often called provers or sequencers, then perform the complex cryptographic work to generate a validity proof for the batch. This process involves creating a polynomial representation of the computation and generating a proof that it was executed correctly without revealing the underlying data. The resulting proof is extremely compact, often just a few hundred bytes, enabling low-cost verification on the settlement layer.

Key technical advantages of this architecture include cost efficiency, as proving costs are amortized across all client rollups; security unification, where multiple chains benefit from the collective cryptographic security of a single, battle-tested proving system; and developer ergonomics, as teams can launch a scalable chain without building proving infrastructure from scratch. Furthermore, a shared prover can facilitate interoperability, as proofs generated under a common system can enable trust-minimized communication between different rollups. This creates a cohesive zkEcosystem where sovereignty and security are not mutually exclusive.

In practice, a project like EigenDA provides data availability, while a shared prover network like RiscZero or Succinct provides the proof computation. A rollup stack might use a shared prover for settlement proofs and a separate shared sequencer for transaction ordering. The economic model typically involves rollups paying fees in a native token or ETH to the prover network for its service. This modular separation aligns with the modular blockchain thesis, which advocates for specializing core functions—execution, settlement, consensus, and data availability—into independent layers to achieve optimal scalability and innovation.

A Shared Prover Architecture is a blockchain scaling design pattern where a dedicated, specialized network of nodes generates cryptographic proofs for transactions executed across multiple, independent blockchains or execution layers. This model separates the roles of transaction execution and proof generation, allowing different chains—often called rollups—to outsource their computationally intensive proving work to a common, optimized marketplace. The core innovation is the creation of a prover-as-a-service economy, where proving resources are not siloed per chain but are pooled for efficiency and cost reduction.

The architecture operates through a clear division of labor. Individual execution layers, such as optimistic rollups or zkEVMs, process user transactions and batch them. Instead of constructing validity proofs internally, they submit these batches to a shared prover network. This network, which runs specialized hardware for tasks like zk-SNARK or zk-STARK generation, competes to produce the proof for a fee. The resulting proof is then returned to the originating chain and verified, typically by its parent Layer 1 blockchain, finalizing the state transition with cryptographic security.

This model offers significant advantages over isolated proving. It creates economies of scale by amortizing high fixed hardware costs across many clients, lowering costs for individual chains. It also enhances decentralization and liveness by preventing a single point of failure; if one prover is offline, others can take its work. Furthermore, it allows execution layers to remain agile and focused on their virtual machines, while leveraging the continuous, rapid advancements in proving hardware and algorithms happening in the shared network.

Key technical components enable this system. A proof marketplace or auction mechanism matches proof jobs with available provers. Standardized proof interfaces and verification contracts ensure proofs generated by any prover in the network are compatible and verifiable by the destination chain. Projects like Espresso Systems with its Espresso Sequencer, GeVul as a shared prover network, and Avail's Nexus interoperability layer exemplify implementations of this architecture, each with variations on coordination and economic models.

The shared prover model is a critical enabler for the modular blockchain thesis, where monolithic chains are decomposed into specialized layers for execution, settlement, consensus, and data availability. By providing proving as a neutral, verifiable utility, it reduces barriers to launching new secure chains and fosters a more interoperable ecosystem. Its success hinges on the security of the proof marketplace, the economic incentives for provers, and the widespread adoption of standard proof formats across the blockchain landscape.