公告：通过选择性披露在以太坊上实现隐私保护的合规检查

ETHTID: Deployable Threshold Information Disclosure on Ethereum

We address the Threshold Information Disclosure (TID) problem on Ethereum: An arbitrary number of users commit to the scheduled disclosure of their individual messages recorded on the Ethereum blockchain if and only if all such messages are disclosed. Before a disclosure, only the original sender of each message should know its contents. To accomplish this, we task a small council with executing a distributed generation and threshold sharing of an asymmetric key pair. The public key can be used to encrypt messages which only become readable once the threshold-shared decryption key is reconstru…

Coconut: Threshold Issuance Selective Disclosure Credentials with Applications to Distributed Ledgers

Coconut is a novel selective disclosure credential scheme supporting distributed threshold issuance, public and private attributes, re-randomization, and multiple unlinkable selective attribute revelations. Coconut integrates with blockchains to ensure confidentiality, authenticity and availability even when a subset of credential issuing authorities are malicious or offline. We implement and evaluate a generic Coconut smart contract library for Chainspace and Ethereum; and present three applications related to anonymous payments, electronic petitions, and distribution of proxies for censorshi…

通过选择性披露授权方案实现公共账本上的隐私保护合规

Privacy-Preserving Compliance on Public Ledgers via Selective Disclosure Authorization Schemes

针对公共账本透明性与数据最小化原则的矛盾，提出选择性披露授权方案（SDAS），通过零知识证明实现细粒度、可撤销的合规检查，并防范前置交易和证明重用攻击。

披露风险评估要求的深入审视

An In-Depth Examination of Requirements for Disclosure Risk Assessment

本文审视披露风险评估要求，提出基于客观标准比较方法，发现反事实框架优于绝对披露风险，近期最适合隐私效用分析。

From t-closeness to differential privacy and vice versa in data anonymization

k-Anonymity and ε-differential privacy are two mainstream privacy models, the former introduced to anonymize data sets and the latter to limit the knowledge gain that results from including one individual in the data set. Whereas basic k-anonymity only protects against identity disclosure, t-closeness was presented as an extension of k-anonymity that also protects against attribute disclosure. We show here that, if not quite equivalent, t-closeness and ε-differential privacy are strongly related to one another when it comes to anonymizing data sets. Specifically, k-anonymity for the quasi-iden…

时间指纹：跨全加密域的身份匹配

Temporal fingerprints: Identity matching across fully encrypted domain

本文提出利用个体事件间隔时间分布作为时间指纹，在以太坊全加密交易平台中实现跨域身份匹配，并证明其优于已有模型，揭示了仅凭活跃时间即可威胁用户隐私的风险。