2025-06-20 –, Main Stage
Anonymous cryptocurrencies face a fundamental challenge: ensuring both integrity and privacy while maintaining scalability. A key issue is the growing storage overhead, as transactions do not reveal spent outputs and requiring additional data to prevent double-spending. We propose a privacy-preserving payment scheme that mitigates this overhead by randomly partitioning unspent outputs into fixed-size bins. Once a bin reaches its reference limit, it is pruned from the ledger, reducing storage while preserving privacy. Our approach leverages smaller untraceability sets rather than the entire set of outputs, improving scalability. We formalize security and privacy for scalable privacy-preserving cryptocurrencies and analyze the role of randomized partitioning in untraceability and efficiency. We instantiate our approach with a Merkle-subtree-based construction that enables efficient proofs and pruning. Additionally, we evaluate the scheme’s resilience against large-scale attacks and discuss open problems, demonstrating how partitioning enhances privacy-preserving cryptocurrency design.
I'm a PhD student in the Cryptology and Data Security Group at the University of Bern. My research focuses on the privacy aspects of digital currencies. My primary concern is developing formal definitions to assess and compare privacy guarantees across various systems, from decentralized permissionless schemes to centrally managed digital currencies. I am committed to designing systems that can provably achieve these privacy guarantees or introduce innovative privacy properties. A significant aspect of my work involves optimizing the efficiency of privacy-preserving cryptocurrency mechanisms. I investigate methods to reduce computational overhead and storage requirements while maintaining strong privacy guarantees. My research also addresses the unique consensus requirements of privacy-preserving cryptocurrencies, where validation must occur without full transaction transparency. I investigate the theoretical boundaries and practical implementations of consensus protocols that can operate with limited information disclosure.