The Rayls Private Network Hub is an EVM blockchain that is the hub connecting each of the Rayls Nodes within a Rayls Private Network. All on-chain messages and transactions flow between Rayls Privacy Nodes via the shared Private Network Hub of the Private Network.

All inter-Privacy Node transactions are encrypted and stored to the Private Network Hub's blockchain ledger, creating an immutable record of transactions that can only be decrypted by the parties directly involved in the transaction (see the EVM Privacy page for more information).

In addition to keeping an immutable record of encrypted transactions, the Private Network Hub also maintains the state of Private Network by validating cryptographic proofs that are regularly submitted by each Rayls Node and enforces the Private Network governance policies, as set by the Private Network Governor.

Purpose

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

1. Legitimacy

On the Private Network Hub, managed by the Private Network Governor, there is a registry of all approved Rayls Node members (the Member Registry) and a registry of all approved tokens that can be transacted across the Private Network (the Token Registry). As Rayls Nodes transact with one another, validation checks can be made against these registries, including checking the status of a specific member or token (i.e. to ensure they are still active, not frozen or deactivated).

For each registered token, a copy of the token's smart contract is stored on the Private Network Hub and automatically deployed on demand to a Rayls Node (via its Relayer) when receiving this token for the first time. This ensures that the token being received is the exact same as the token that was registered (not a fake) and also enables smoother token upgradability, where updates can be made to the token contract on the Private Network Hub and broadcast to the Rayls Privacy Node Ledgers of the Private Network.

Similarly, when a Rayls Node is receiving a token, there is a validation step to ensure that the token was indeed minted by the original Issuer (the Rayls Node that originally minted and registered the token, not a fake).

2. Validity

To ensure transaction validity, preventing fraud or double spend, Rayls imposes validation steps that occur during every transaction, utilising cryptographic proofs that are submitted by the transacting Rayls Nodes.

There are two main proofs that are compared to conduct this validation:

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

Automated validation checks are conducted for each transaction to compare the transaction proofs with the latest time-based state commits to ensure that the transaction is valid (there has been no double spend nor fraudulent activity). If a transaction is not valid, it will fail and the issue will be identified by the Flagger.

3. Consistency

The Private Network Hub is the single source of truth for all (encrypted) messages and transactions across the Private Network - all inter-Privacy Node transactions are recorded to the Private Network Hub ledger. By comparing the various cryptographic proofs submitted by Rayls Nodes (time-based state commits and transaction proofs) the Private Network Hub can ensure the consistency of state across the Private Network.

As all tokens that are transferred between Rayls Nodes are registered with the Private Network Hub (including their total minted supply), the Private Network Hub can compare these reference points using ZK to validate the total circulating supply and net balances of each registered token and ensure that this is consistent with the network state, further preventing fraud and double spend within the Private Network.

Core Functions

1. Transaction Coordination

The Rayls Private Network Hub is responsible for managing and validating transactions between Rayls Nodes. It ensures that transactions are consistent, tamper-proof, and follow the rules and protocols set by the network governance.

Validation: The Private Network Hub validates transactions to ensure they meet all necessary criteria before being committed.
Atomicity: Supports atomic transactions, ensuring that all parts of a transaction are completed successfully, or none are, preventing partial execution.

2. Finality and Proofs

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

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

3. Privacy and Security

Maintaining privacy and security is a top priority for the Rayls Private Network Hub. It ensures that transaction details are kept confidential while still allowing necessary validations and audits.

Confidential Transactions: Transaction details are encrypted and only visible to authorised parties, protecting 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 facilitates cross-chain interoperability between Rayls Nodes (as each Rayls Privacy Node Ledger is itself an independent blockchain), enabling secure and efficient cross-chain transactions.

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

Governance and Control

The Rayls Private Network Hub includes robust governance mechanisms to ensure that all transactions and operations within the network adhere to established rules and standards.

1. Governance Policies

Governance policies are enforced programmatically via smart contracts, ensuring that all transactions and operations comply with the network’s rules.

Policy Enforcement: Smart contracts automatically enforce governance policies, reducing the risk of human error and ensuring consistency. These governance contracts can only be implemented and amended by the Private Network Governor.
Customisable Policies: Governance policies, determined by the Private Network Governor, can be tailored to meet the specific needs of different users and regulatory environments.

2. Control Mechanisms

The Private Network Hub includes control mechanisms that allow for the freezing, locking, and seizing of assets when necessary, providing additional layers of security and compliance.

Asset Freezing: Temporarily halts the transfer of specific assets to prevent unauthorized transactions or fraud.
Asset Locking: Restricts access to certain assets under specific conditions, ensuring 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 designed to handle high transaction volumes, providing scalability to meet the needs of large financial institutions and other enterprise users.

Depending on the blockchain platform selected for the Private Network Hub (it can be any EVM-based platform, but we recommend Hyperledger Besu), transaction throughput may be limited by the TPS of that platform.

To overcome this limitation, Rayls provides an efficient batching approach such that transactions (thousands) are batched by the sending Rayls Node and the batch is then posted to the Private Network Hub as a single transaction.

As such, the TPS of the Private Network overall can be in the tens of thousands of transactions per second (depending on configuration and transaction types), which more than satisfies the throughput requirements of inter-financial institution settlement.

Conclusion

The Rayls Private Network Hub is a powerful and essential component of the Rayls ecosystem, ensuring the legitimacy, validity and consistency of the Private Network to support next-generation financial transactions. By acting as a secure hub that connects the Private Network's Rayls Nodes, the Private Network Hub ensures that all transactions are validated, recorded, and governed according to the highest standards of privacy and compliance.

For more information on how to use the Rayls ecosystem in your operations, please refer to our detailed integration guides and API documentation.