RISC-V proving architecture

LinethLineth (Formerly the Linea Stack) The open-source ZK-rollup stack, codebase, and technical protocol that's the foundation of Linea Mainnet. Operators can deploy this stack to launch their own Ethereum-compatible L2 or L3 networks. is evolving toward a RISC-V-based proving architecture. In this proving context, RISC-V is the execution target for guest programs: programs that define the computation the protocol needs to prove. Instead of representing every proving task only through custom constraints and circuits, a guest program can be compiled to RISC-V, executed in the Lineth proving system, and composed into the broader proof-generation flow.

Status

RISC-V proving is in development and is not yet part of the proving path in any Lineth deployment.

Why RISC-V matters for proving

RISC-V is an open instruction-set architecture. In a proving system, it can provide a common execution target for programs that need to be proven.

Using RISC-V as a proving target enables Lineth to represent proof logic as guest programs. A guest program defines the computation to prove, compiles to RISC-V, and runs inside the Lineth proving system, which can produce a proof for that computation.

This creates a clearer boundary between the program being proven and the Lineth proving system that executes and proves it.

This boundary is important for Ethereum compatibility. EVM upgrades and forks can change the execution behavior the protocol needs to prove. With a RISC-V model, guest programs can encode those execution-rule changes in program logic, which can make backward compatibility and EVM upgrade support easier than reshaping broad parts of custom proving constraints or circuits for each EVM change.

Relationship to the prover

The prover generates the proofs that support protocol correctness guarantees. The current proof-generation path is organized around execution proofs, compression proofs, aggregation proofs, trace expansion, and circuit execution and runtime.

The RISC-V architecture is an evolution within the prover role. It is designed to change the proving target and the way proof-generating programs are represented, while preserving the prover's high-level purpose: producing proofs that let the network verify state transitions. The coordinator still orchestrates proof generation and finality submission according to the network's deployment model.

Therefore, RISC-V is part of the prover architecture, not a standalone deployment model or access-control feature.

High-level flow

At a high level, the planned RISC-V proving architecture follows this flow:

1. A guest program defines the computation that must be proven, such as EVM execution logic.
2. The guest program is compiled to RISC-V.
3. The Lineth proving system executes the RISC-V program and produces a proof for that computation.
4. Proofs can be composed into the broader proof-generation flow.
5. The coordinator submits the resulting proof data to the finalization layerFinalization layer The blockchain where a Lineth deployment submits proofs and state commitments for verification and hard finality. If the finalization layer is Ethereum (an L1), the deployment is an L2. If the finalization layer is Linea (an L2), the deployment is an L3. according to the network's deployment model.

At the protocol level, Lineth still proves that state transitions are valid and finalizes those proofs through the configured finalization layer.