2021-10-04-香港金融管理局-零售层面央行数字货币的技术白皮书_50页_3mb

Summary of HKMA's e-HKD Technical Whitepaper

The Hong Kong Monetary Authority (HKMA) has initiated Project e-HKD, a feasibility study on the retail or general-purpose central bank digital currency (rCBDC) to explore potential benefits and risks. This project is part of a broader effort, including collaborations with institutions like the Central Bank of the UAE, BISIH Hong Kong Centre, and the People's Bank of China, to advance wholesale CBDC research.

1. Background:

• e-HKD Objectives: To assess the feasibility, benefits, and risks of rCBDC, focusing on legal, operational, and technological aspects.
• Project Aurum: A proof-of-concept study exploring architecture models for rCBDC and CBDC-backed e-money.
• Two-Tier Architecture: Proposed design separates a central bank-operated wholesale system for issuing and redeeming CBDC, from a retail system managed by intermediaries ("banks and PSPs").

2. Technology Challenges and Solutions:

• Decoupling Mechanisms: Isolating wholesale and retail layers to enhance cybersecurity.
• Cross-Ledger Synchronization: Ensuring operational integrity and preventing over-issuance via consensus mechanisms.
• Privacy-Preserving Transactions: Incorporating pseudonym systems with dynamically evolving public keys to safeguard user identities.
• Scalability: Using DLT platforms like Corda or Hyperledger Fabric optimized for transaction throughput.

3. Key Concepts:

• e-HKD Functionality: Users hold rCBDC in accounts or as UTI囯 transactions, secured by validator infrastructure endpoints.
• Validator Infrastructure: A critical UTXO database implementing digital signatures and validating transactions to enforce rules.
• UTXO Model: Supporting both token-based and account-based transactions explicitly for traceability and programmability.
• Efficiency and Energy: Avoiding "Proof-of–Work" protocols to ensure energy-efficient transactions compared to Bitcoin.
• Security Focus: Implementing data diodes, sufficient decoupling, and redundancy to protect central bank operations and ledger integrity.

4. Solicitation of Input:

HKMA has invited the wider fintech community, academia and industry to:

• Comment on the proposed technical architecture.
• Innovate solutions addressing seven key problem areas: privacy preservation, cross-platform interoperability, performance optimizations, cybersecurity strategies, regulatory compliance mechanisms, operational fault tolerance, and enablement of technological advancements.

5. Next Steps and Future Work:

• Experimentation: Due diligence on trade-offs between different systems, cryptographic methods and ongoing iteration based on community proposals and research advancements.
• RFC Paper: Follows the guidance of the scholarly community analogous to Internet RFC documents in inviting peer feedback on IoT and security structures.