The Rayls Private Network Hub is an EVM blockchain that connects each of the Rayls Nodes within a Rayls Private Network. All onchain messages and transactions flow between Rayls Nodes through the shared Private Network Hub of that Private Network.

All transactions between Rayls Nodes are encrypted and stored to the Private Network Hub's blockchain ledger, which creates an immutable record that can only be decrypted by the parties directly involved in the transaction (the EVM Privacy page covers this in more detail).

Alongside keeping an immutable record of encrypted transactions, the Private Network Hub maintains the state of the Private Network by validating cryptographic proofs submitted by each Rayls Node, and it enforces the Private Network governance policies set by the Private Network Operator.

Purpose

The Private Network Hub therefore ensures the legitimacy, validity and consistency of the state and interactions across the Private Network.

1. Legitimacy

The Private Network Hub, managed by the Private Network Operator, holds a registry of every approved Rayls Node member (the Member Registry) and a registry of every approved token that can be transacted across the Private Network (the Token Registry). As Rayls Nodes transact with one another, validation checks are made against these registries, including checks on the status of a specific member or token to confirm that it is still active rather than frozen or deactivated.

For each registered token, a copy of the token's smart contract is stored on the Private Network Hub and deployed automatically to a Rayls Node, through its Relayer, when that node receives the token for the first time. This confirms that the token being received is the same token that was registered rather than a counterfeit, and it makes upgrades straightforward, since an update to the token contract on the Private Network Hub can be broadcast to the Rayls Sovereign ledgers across the Private Network.

There is a further validation step when a Rayls Node receives a token, which confirms that the token was minted by the original Issuer, meaning the Rayls Node that first minted and registered it.

2. Validity

To establish transaction validity and guard against fraud or double spend, Rayls applies validation steps during each transaction using cryptographic proofs submitted by the transacting Rayls Nodes.

Two proofs are compared to carry out that validation:

Time-based state commits: a Sovereign ledger's internal block headers are published as a proof to the Private Network Hub every few seconds
Transaction proofs: submitted by both sending Sovereign ledger and receiving Sovereign ledger as part of each inter-Sovereign transaction across the Private Network Hub, orchestrated by the Rayls Protocol

Automated checks compare the transaction proofs against the latest time-based state commits to establish that a transaction is valid and that no double spend or fraudulent activity has occurred. Where a transaction is not valid, it fails and the issue is identified by the Flagger.

3. Consistency

The Private Network Hub is the single source of truth for every encrypted message and transaction across the Private Network, and all transactions between Rayls Nodes are recorded to the Private Network Hub ledger. By comparing the cryptographic proofs submitted by Rayls Nodes, meaning the time-based state commits alongside the transaction proofs, the Private Network Hub establishes the consistency of state across the Private Network.

Because every token transferred between Rayls Nodes is registered with the Private Network Hub, including its total minted supply, the Private Network Hub can compare those reference points using ZK proofs to validate the total circulating supply and the net balances of each registered token, confirming that both are consistent with network state and adding a further check against fraud and double spend.

Core Functions

1. Transaction Coordination

The Rayls Private Network Hub manages and validates transactions between Rayls Nodes, keeping them consistent, tamper-proof and aligned with the rules and protocols set by network governance.

Validation: The Private Network Hub validates transactions to confirm they meet all necessary criteria before being committed.
Atomicity: Supports atomic transactions, so that every part of a transaction completes or none of it does, which rules out partial execution.

2. Finality and Proofs

The Private Network Hub provides immutable transaction finality, so that once a transaction is included on the Private Network Hub ledger it cannot be altered or reversed. It also manages the cryptographic proofs that establish the integrity and validity of transactions.

Proofs Management: Handles the creation and storage of cryptographic proofs used to verify the authenticity of transactions.
Immutability: Once a transaction is committed it becomes a permanent part of the blockchain, giving a transparent and tamper-proof record.

3. Privacy and Security

Privacy and security are a first-order concern for the Rayls Private Network Hub, which keeps transaction details confidential while still allowing the validations and audits the network depends on.

Confidential Transactions: Transaction details are encrypted and visible only to authorised parties, which protects sensitive information.
Regulatory Compliance: The Private Network Hub supports compliance with legal and regulatory requirements by enabling secure and transparent audit trails.

4. Interoperability

The Rayls Private Network Hub supports cross-chain interoperability between Rayls Nodes, since each Rayls Sovereign ledger is itself an independent blockchain, and it does so while preserving the security of each transaction.

Cross-Chain Transactions: Supports the execution of transactions across different blockchains, maintaining privacy and security throughout the process.
Interoperable Protocols: Compatible with a range of blockchain protocols to support composability and ease of integration.

Governance and Control

The Rayls Private Network Hub carries governance mechanisms that hold every transaction and operation within the network to the established rules and standards.

1. Governance Policies

Governance policies are enforced programmatically through smart contracts, so that all transactions and operations comply with the rules of the network.

Policy Enforcement: Smart contracts enforce governance policies automatically, which reduces the risk of human error and keeps enforcement consistent. These governance contracts can only be implemented and amended by the Private Network Operator.
Customisable Policies: Governance policies, determined by the Private Network Operator, can be tailored to the needs of different users and regulatory environments.

2. Control Mechanisms

The Private Network Hub includes control mechanisms for freezing, locking and seizing assets where that is required, which adds further layers of security and compliance.

Asset Freezing: Temporarily halts the transfer of specific assets to prevent unauthorised transactions or fraud.
Asset Locking: Restricts access to certain assets under specific conditions, so that they are only used as intended. Feature coming soon
Asset Seizing: Allows for the seizure of assets in accordance with legal and regulatory requirements. Feature coming soon

Scalability and Performance

The Rayls Private Network Hub is built for high transaction volumes, giving the scalability that large financial institutions and other enterprise users require.

Throughput may be limited by the TPS of the blockchain platform selected for the Private Network Hub, which can be any EVM-based platform, although Rayls recommends Hyperledger Besu.

Rayls addresses that limit with a batching approach, where thousands of transactions are batched by the sending Rayls Node and the batch is then posted to the Private Network Hub as a single transaction.

With batching in place, the Private Network supports 15,000+ TPS with sub-second finality, depending on configuration and transaction types, which sits comfortably above the throughput requirements of inter-institution settlement.

Conclusion

The Rayls Private Network Hub connects the Rayls Nodes of a Private Network and holds the legitimacy, validity and consistency of that network in one place, validating, recording and governing every transaction that crosses it.

Further detail on running Rayls in production sits in the Rayls integration guides and the Rayls API documentation.