Service Overview

Archival

Provides long-term storage of FBDAs that have been retired.

Authority

Authorities utilize the Authority Service to:

• Control the issuance of FBDAs against reserve accounts
• Cryptographically authorize new FBDAs upon issuance
• Redemption of FBDAs when requested by the Authorized Intermediary

Gateway

The payment network operator operates the Knox Gateway which connects entities all at the interbank level and provides streaming and security services for the network. The Gateway Service can serve as a way for Authorities and Authorized Intermediary to both monitor network health and guard against cyber attacks in the Knox Networks system. The Gateway Service can be run by a network operator that may be the Authority directly, a third party, or delegated to particularly important Authorized Intermediaries (e.g. GSIBs or commercial bank divisions).

Distributor

The Distributor Service is run by Authorized Intermediaries and oversees the distribution of FBDAs into circulation. Through the Distributor Service, Authorized Distributors can:

• Distributes and redeem FBDAs into and out of the system, under limits from the Authority
• Handles the distribution process of FBDAs to retail wallets
• Replaces FBDAs in circulation once they reach a configurable size threshold

Treasury

The Treasury Service oversees the management of holding multiple currencies, remittances, and other assets.

• Remits FBDAs denominated in domestic and foreign currencies
• Handles residual change distributions (change-making)
• Holds FBDAs denominated in various currencies.

Mobile/Custodial Wallets

Wallets allow for the storing and transferring of FBDAs and digital identity credentials. Mobile Wallets are end-user managed, and Custodial Wallets are bank-managed.

The Custodial Wallet Service transacts and holds FBDAs and bank customer information. This is the server-side version of the Digital Wallet that is hosted by the bank on behalf of customers. This wallet can provide bank customers with custodial accounts and interoperability with existing account-based systems. This system can allow for the storage of active FBDAs that belong to particular accounts, and for managing the transferring of FBDAs between accounts as necessary.

The Mobile Wallet Service similarly transacts and holds FBDAs and bank customer information. This is the client-side version of the Digital Wallet that is hosted by retail users on their mobile devices, and allows for Offline Transactions. This wallet can provide privacy-preserving identity services for users. This system can allow for the storage of active FBDAs that belong to particular users, and for managing the transferring of FBDAs between accounts as necessary.

Transaction Validator

The Transaction Validator Service processes transactions via two sub-services which perform complementary but distinct tasks: (1) the Transaction Manager Sub-Service coordinates and reasons about the status of the transaction, and (2) the Notary Sub-Service carries out the instruction of transactions.

The Transaction Manager Sub-Service is a robust solution for allowing programmability into the Knox system via overseeing the management Contract-Based Transaction. Utilizing the Transaction Manager Service for Contract-Based Transactions allows for more complex transaction types to be built out, including atomic transactions such as Delivery vs. Payment and Payment vs. Payment. The Transaction Manager Sub-Service sends over authorization or rollback instructions to the Notary Sub-Service depending on fulfillment or violation of commitments.

The Notary Sub-Service is a highly-scalable method for validating transactions under jurisdiction from either the Authority or from an Authorized Intermediary. This horizontal scaling is possible because each FBDA is an independent proof-of-ownership, allowing for transactions of FBDAs to occur independently of one another (and therefore concurrently). The Notary Sub-Service can provide Authorization Signatures on FBDAs upon transfer.

Advanced Services

Knox’s flexibility allows for the easy introduction of extensible value add services. Examples of services that could be created on the Knox system include Sanctions Screening and Analytics.