An auditable and privacy-preserving user-controllable group signature scheme in blockchain

In recent years, the rapid development of Internet information technology has also brought about numerous challenges, with one of the most prominent being data security. In current information systems, platforms control critical data but rely on centralized architectures. As a result, data usage cannot be effectively monitored, leading to issues such as insecure storage and privacy breaches, which are especially critical in financial transaction systems. In this paper, we propose and implement a group signature model based on user behavior. This model maps privacy preservation levels to users’ transaction amounts, achieving a dynamic and user-perceivable multi-level privacy preservation mechanism. As users’ transaction amounts increase, the privacy preservation level of the group signature gradually enhances, allowing authorized parties to reveal more user privacy information. The proposed scheme achieves a balance between user privacy preservation and regulatory, offering a more flexible solution for modern Internet trading systems. To validate the practicality of this group signature, we developed a blockchain-based knowledge payment platform to address issues of data abuse and data leakage in existing knowledge payment platforms. Security and performance analyses confirm the practicality and effectiveness of the proposed scheme.