发表机构
Graduate School of Information Science and Technology, The University of Osaka; Faculty of Materials for Energy, Shimane University（大阪大学信息科学技术研究生院; 岛根大学能源材料学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对匿名网络中匿名性与问责制难以调和的问题，提出Lacan协议，通过路径外受托人、后继证明链等技术实现二者兼顾，减少公钥操作并验证了性能。
AI 中文摘要
匿名性和问责制是我们日常互联网活动的基本属性，但二者看似矛盾，调和二者的目标仍远未实现。现有方法在这方面存在不足，要么依赖路径上的受托人，要么依赖每数据包授权、每数据包公钥密码学，要么依赖中央机构的每会话干预。我们提出Lacan协议，它在现实设计中调和了匿名性与问责制。在Lacan中，只要发送方遵守与接收方订立的合约，就能通过路径上的中继获得匿名性。当合约被违反时，代表接收方的路径外受托人（验证方）会通过数据包、路径和会话间接将恶意消息与发送方身份关联，从而将公钥操作从每数据包减少到每会话。这种关联即使在对抗恶意中继和恶意接收方时也保持鲁棒性，其基础是我们提出的用于问责路径重建的新型后继证明链，以及可追踪签名、路径验证和密钥承诺加密。我们分析了匿名性和问责制，实现了该协议并评估了其性能。
英文摘要
Anonymity and accountability are essential properties for our everyday activity on the Internet. However, they appear contradictory, and their reconciliation remains far from reality. Existing approaches fall short in this regard, as they either rely on an on-path trustee, per-packet authorization, per-packet public-key cryptography, or per-session intervention by a central authority. We propose Lacan, a protocol that reconciles anonymity and accountability within a realistic design. In Lacan, a sender enjoys anonymity provided by on-path relays, as long as she complies with a contract established with the receiver. Upon a contract violation, the verifier, an off-path trustee on behalf of the receiver, links the malicious message to the sender's identity indirectly via the packet, path, and session, thereby reducing public-key operations from per-packet to per-session. This linkage remains robust even against malicious relays and receivers, grounded in our novel chain of successor proofs for accountable path reconstruction, together with traceable signatures, path validation, and key-committing encryption. We analyze the anonymity and accountability, implement the protocol, and evaluate the performance.
