> For the complete Linea documentation index, see [llms.txt](/llms.txt). > Agents can fetch this page as Markdown at [https://docs.linea.build/stack/features/validium.md](https://docs.linea.build/stack/features/validium.md). # Privacy Private Validium is a deployment model for the Linea stack that keeps transaction data offchain while maintaining cryptographic guarantees through zero-knowledge proofs. It is designed for regulated financial institutions and applications requiring privacy, compliance controls, and selective data disclosure. important [Reach out](https://forms.gle/eip4XrYhPFDuLtDQ8) to enquire about rollup-as-a-service, wherein all or part of the operations are supported by Linea and its partners. ### Validium differentiators In validium mode, the Linea network proves state transitions using zk-SNARKs while retaining transaction data within a private data availability layer. After blocks are produced by the sequencer, they are aggregated and batched, and a zk-SNARK proof attesting to the resulting state transition is generated and submitted to the finalization layer. ## Key features ### Offchain data availability Transaction data is stored offchain in a private node set rather than posted to the finalization layer. Only state commitments and zero-knowledge proofs are posted onchain, ensuring transaction privacy while maintaining cryptographic guarantees. ### Role-based access control Role-Based Access Control (RBAC) controls access to network functionality: - RPC endpoints: Access controlled by API keys and permissions - API portal: Institution-level access controls - Transaction visibility: Participants see only transactions they're authorized to view ### Privacy and compliance Private Validium supports regulated financial applications: - Transaction privacy: Transaction details not visible on finalization layer - Selective disclosure: Authorized parties (auditors, regulators) can access transaction data - Compliance controls: Compliance checks can be enforced at the API and sequencer levels - Audit trails: Complete audit trails while maintaining privacy ### API portal The API portal provides controlled access to network functionality: - Institution onboarding and management - Token issuance and management - Settlement workflows (CBP, PVP, DVP) - Balance queries and reporting ### Finalization layer options Private Validium can finalize on: - Ethereum L1: direct finalization on Ethereum with higher costs and longer finality times - Linea Mainnet: finalization on Linea Mainnet with lower costs and faster finality See [a comparison of finalization layer options](/stack/how-it-works/data-availability-finalization#finalization-layer). ## Use cases Private Validium is ideal for: - Regulated financial institutions: Banks, payment processors, and financial market infrastructures requiring compliance and privacy - Multi-party workflows: Applications where participants should not see all transaction details - Tokenized assets: Issuance and settlement of tokenized securities and cash - Cross-border payments: Settlement systems requiring privacy and compliance controls ## Architecture Private Validium deployments include: - Consensus layer: [Maru](/protocol/reference/repos#maru) with Quorum-Based Byzantine Fault Tolerance (QBFT) consensus (minimum 4 nodes, see [distributed sequencing](/stack/how-to/distributed-sequencing)) - Execution layer: [Linea Besu](/protocol/reference/repos#linea-besu-upstream) with sequencer plugins - [Coordinator](/protocol/architecture/coordinator): Orchestrates proof generation and [finalization](/network/overview/transaction-finality) - [Prover](/protocol/architecture/prover): Generates zero-knowledge proofs - [State manager](/protocol/architecture/state-manager): Maintains state for proof generation - Private RPC nodes: RBAC-protected RPC endpoints - API portal: Controlled access to network functionality - Data availability: Private node set for data storage ## Security and trust ### Trust assumptions Private Validium requires trust in: - Data availability providers: Must make data available when needed - Validator set: Must follow consensus protocol (QBFT provides fault tolerance) - Finalization layer: Inherits security from Ethereum ### Security features - Minimum node count: 4 nodes for QBFT fault tolerance - Access controls: Role-Based Access control (RBAC) on RPC and API endpoints - Key management: Supports [Web3Signer](/protocol/architecture#web3signer) remote signing backed by a hardware security module (HSM) or key management service (KMS) - Network isolation: Private network topology ### Data availability Where deployments use a private node set for data storage, participants must trust that data availability providers will make data available when needed. ## Next steps - Learn more about selecting a [deployment model](/stack/how-it-works/deployment-models)