Blind Multisignatures for Anonymous Tokens with Decentralized Issuance
发表信息
作者
- Ioanna Karantaidou
- Omar Renawi
- Foteini Baldimtsi
- Nikolaos Kamarinakis
- Jonathan Katz
- Julian Loss
笔记
We propose the first constructions of anonymous tokens with decentralized issuance. Namely, we consider a dynamic set of signers/issuers; a user can obtain a token from any subset of the signers, which is publicly verifiable and unlinkable to the issuance process. To realize this new primitive we formalize the notion of blind multi-signatures (BMS), which allow a user to interact with multiple signers to obtain a (compact) signature; even if all the signers collude they are unable to link a signature to an interaction with any of them. We then present two BMS constructions, one based on BLS signatures and a second based on discrete logarithms without pairings. We prove security of both our constructions in the Algebraic Group Model. We also provide a proof-of-concept implementation and show that it has low-cost verification, which is the most critical operation in blockchain applications.
我们提出了首个具有去中心化发行功能的匿名令牌(anonymous tokens)构造方案。具体而言，我们考虑一个动态的签名者/发行者集合；用户可以从签名者的任意子集获得令牌，该令牌可公开验证且与发行过程不可关联。为实现这一新型原语，我们形式化定义了盲多重签名(blind multi-signatures, BMS)的概念，它允许用户与多个签名者交互以获得一个（紧凑的）签名；即使所有签名者串通，他们也无法将签名与任何一次交互关联起来。随后，我们提出了两种BMS构造方案，一种基于BLS签名(BLS signatures)，另一种基于不需要配对运算的离散对数(discrete logarithms)。我们在代数群模型(Algebraic Group Model)中证明了这两种构造方案的安全性。我们还提供了概念验证实现，并表明它具有低成本的验证操作，这是区块链应用中最关键的操作。