As global governments intensify efforts to operationalize retail central bank digital currencies (CBDCs), the imperative for architectures that preserve user privacy has never been more pronounced. This paper advances an existing retail CBDC framework developed at University College London. Utilizing the capabilities of the Comet research framework, our proposed design allows users to retain direct custody of their assets without the need for intermediary service providers, all while preserving transactional anonymity. The study unveils a novel technique to expedite the retrieval of Proof of Provenance, significantly accelerating the verification of transaction legitimacy through the refinement of Merkle Trie structures. In parallel, we introduce a streamlined Digital Ledger designed to offer fast, immutable, and decentralized transaction validation within a permissioned ecosystem. The ultimate objective of this research is to benchmark the performance of the legacy system formulated by the original Comet research team against the newly devised system elucidated in this paper. Our endeavour is to establish a foundational design for a scalable national infrastructure proficient in seamlessly processing thousands of transactions in real-time, without compromising consumer privacy or data integrity.

翻译：随着各国政府大力推进零售中央银行数字货币（CBDC）的运营化，保护用户隐私的架构需求变得前所未有的迫切。本文在伦敦大学学院开发的现有零售CBDC框架基础上进行改进。利用Comet研究框架的能力，我们提出的设计允许用户无需中介服务提供商即可直接托管资产，同时保持交易匿名性。本研究揭示了一种加速来源证明检索的新技术，通过优化Merkle Trie结构显著提升交易合法性验证效率。同时，我们引入了一个精简的数字账本，旨在许可生态系统中实现快速、不可篡改且去中心化的交易验证。本研究的最终目标是对原始Comet研究团队制定的传统系统与本文阐述的新设计系统进行性能基准测试。我们的努力旨在为可扩展的国家基础设施奠定基础设计，使其能够在不损害消费者隐私或数据完整性的情况下，无缝实时处理数千笔交易。