论文标题
基于政策的可追溯签名和实例化
Traceable Policy-Based Signatures and Instantiation from Lattices
论文作者
论文摘要
Bellare和Fuchsbauer（PKC 2014）提出了基于策略的签名（PBS），以允许组织的{\ em授权}成员代表组织签署消息。用户的授权由由组织可信赖的权威管理的策略决定，而签名则保留了组织政策的隐私。 PBS中的签名密钥不包括用户身份信息，因此可以传递给他人，违反了使用PBS来限制用户签名功能的意图。 在本文中，我们通过在签名密钥中包括用户身份来介绍PBS {\ em Traceabiality}的概念，以便值得信赖的当局能够打开可疑签名并在出现需求时恢复签名者的身份。我们提供了可追溯PBS（TPB）的严格定义和严格的安全性概念，捕获了Bellare-Fuchsbauer建议的PBS的属性，并类似于Bellare-Micciancio-Warinschi（Eurocrypt2003）提出的“完整可食用性”要求。作为概念证明，我们根据签名方案，加密方案和零知识证明系统提供了TPB的模块化构造。此外，为了证明从混凝土，抗量子的假设中实现TPB的可行性，我们给出了基于晶格的实例化。
Policy-based signatures (PBS) were proposed by Bellare and Fuchsbauer (PKC 2014) to allow an {\em authorized} member of an organization to sign a message on behalf of the organization. The user's authorization is determined by a policy managed by the organization's trusted authority, while the signature preserves the privacy of the organization's policy. Signing keys in PBS do not include user identity information and thus can be passed to others, violating the intention of employing PBS to restrict users' signing capability. In this paper, we introduce the notion of {\em traceability} for PBS by including user identity in the signing key such that the trusted authority will be able to open a suspicious signature and recover the signer's identity should the needs arise. We provide rigorous definitions and stringent security notions of traceable PBS (TPBS), capturing the properties of PBS suggested by Bellare-Fuchsbauer and resembling the "full traceability" requirement for group signatures put forward by Bellare-Micciancio-Warinschi (Eurocrypt 2003). As a proof of concept, we provide a modular construction of TPBS, based on a signature scheme, an encryption scheme and a zero-knowledge proof system. Furthermore, to demonstrate the feasibility of achieving TPBS from concrete, quantum-resistant assumptions, we give an instantiation based on lattices.
