Evaluate Lineth

This page describes 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. capabilities that matter when evaluating a deployment, and points to the pages that go deeper on each one. For design choices and operator responsibilities, continue to deployment architecture.

What Lineth provides​

Lineth is a ZK-rollupZero-knowledge rollup An L2 scaling solution that uses a zero-knowledge proof as its validity proof to post data back to Ethereum. As compared to optimistic rollups, this validity proof allows for a more secure trust assumption and removes the need for a challenge period. stack. A deployment combines a consensus layer, an execution layer, a proverProver The Lineth component that generates ZK proofs of state transitions, handling proof-generation requests from the coordinator and Linea Besu. The prover produces three types of proofs (execution, compression, and aggregation) and combines them into a zk-SNARK that the finalization layer verifies. Provers may be scaled horizontally to meet throughput requirements., a coordinatorCoordinator Lineth's coordination module for batching, proof generation, and finality submission. The coordinator monitors block production, manages conflation deadlines, batches blocks, combines batches into blobs, orchestrates execution, compression, and aggregation proofs, and submits proofs and data to the finalization layer., and a set of onchain contracts on a 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.. Operators choose the deployment model, data availability arrangement, finalization layer, and access controls.

The following capabilities depend on the deployment model chosen.

Deployment model capabilities​

Using Lineth, an operator can deploy:

• Public networks, such as Linea Mainnet, with onchain data availability.
• Private validium networks, with offchain data availability and controlled access.

For the trade-offs between these models, see Deployment models.

Protocol capabilities​

State transition correctness​

Lineth uses zk-SNARKzk-SNARK (Zero-Knowledge Succinct Non-interactive Argument of Knowledge) A type of ZK proof where the prover and verifier don't have to interact. With zk-SNARKs, you can verify 1 transaction or 1 billion transactions in the same amount of time. proofs to verify that state transitions are valid. A valid proof means the operator cannot finalize an invalid state transition through the normal proof path. Proofs do not by themselves make transaction contents private; data visibility depends on the deployment's data availability and access model. For the data-visibility distinction, see Privacy and data visibility.

EVM-compatible execution​

Lineth runs EVM-compatible contract execution, so existing Solidity contracts and Ethereum tooling generally work. Compatibility is constrained by the deployment's configuration and by the differences between any chain and Ethereum. For the differences between Linea and Ethereum, see Linea and Ethereum.

QBFT consensus​

For deployments that use multi-validator consensus, Lineth supports QBFTQuorum Byzantine Fault Tolerance (QBFT) The Byzantine-fault-tolerant consensus algorithm that Maru implements to let a validator set produce and finalize blocks, tolerating faulty validators in a 3f+1 validator set., which provides:

• Fault tolerance with 3f+1 validators, tolerating f faulty validators
• Single-slot finality under the deployment's QBFT safety assumptions
• Distributed block production when enough validators participate

Single-validator deployments do not use QBFT and rely on the operator trust model instead. For design trade-offs, topology, and latency, see Multi-validator consensus. For trust assumptions per model, see Trust and responsibilities.

Dual-layer architecture​

Lineth separates consensus and execution. This lets operators choose different client configurations and scale consensus and execution independently. It does not by itself provide client diversity or network resilience; those depend on the operator's deployment.

Where to go next​