Electronic Bill (E-Bill) is a rucial negotiable instrument in the form of data messages, relying on the Electronic Bill System (EB System). Blockchain technology offers inherent data sharing capabilities, so it is increasingly being adopted by small and medium-sized enterprises (SMEs) in the supply chain to build EB systems. However, the blockchain-based E-Bill still face significant challenges: the E-Bill is difficult to split, like non-fungible tokens (NFTs), and sensitive information such as amounts always be exposed on the blockchain. Therefore, to address these issues, we propose a novel data structure called Reverse-HashTree for Re-storing transactions in blockchain. In addition, we employ a variant of the Paillier public-key cryptosystem to ensure transaction validity without decryption, thus preserving privacy. Building upon these innovations, we designed BillChain, an EB system that enhances supply chain finance by providing privacy-preserving and splitting-enabled E-Bills on the blockchain. This work offers a comprehensive and innovative solution to the challenges faced by E-Bills applied in blockchain in the context of supply chain finance.

翻译：电子汇票是一种以数据电文形式存在的关键可流通票据，其运行依赖于电子票据系统。区块链技术因其天然的数据共享特性，正越来越多地被供应链中的中小企业用于构建电子票据系统。然而，基于区块链的电子汇票仍面临重大挑战：电子汇票如同非同质化代币（NFTs）难以拆分，且金额等敏感信息始终暴露在区块链上。为此，我们提出一种名为反转哈希树的新型数据结构，用于重构区块链中的交易存储方式。同时，我们采用Paillier公钥密码系统的变体，在不解密的情况下确保交易有效性，从而保护隐私。基于这些创新，我们设计了BillChain——一个通过在区块链上提供隐私保护且支持拆分功能的电子汇票来增强供应链金融的电子票据系统。本工作为电子汇票在供应链金融场景中应用于区块链所面临的挑战提供了全面创新的解决方案。