一种前向安全的盲币协议设计与分析

Design and Analysis of a Forward Security Blindcoin Protocol

为防止攻击者发现比特币地址与虚拟用户身份信息之间的关系,针对密码协议已经出现了许多匿名化和混币技术.目前常见的中心化混币协议有Mixcoin协议、Blindcoin协议,但是这些协议存在时延较长、混淆请求者多、易遭受拒绝服务攻击、自适应攻击等问题.为解决这些问题,设计了一种具有高效的、存储效率低并且防自适应攻击的盲币协议.该方案利用盲签名技术不但为中心化混币提供了内部隐私性,而且通过签名密钥更新实现了前向安全性,能够防止自适应攻击.此外,通过安全性分析和性能评估,证明了方案的安全性和有效性.

To prevent attackers from discovering the relationship between Bitcoin addresses and virtual user identity information, many anonymization and currency mixing techniques have been developed for cryptographic protocols. At present, the common centralized currency mixing protocols include the Mixcoin protocol and the Blindcoin protocol, but these protocols have problems such as long time delay, large number of confusing requesters, and vulnerability to denial of service attacks and adaptive attacks. To address these issues, we design a Blindcoin protocol that is efficient, storage-inefficient, and resistant to adaptive attacks. This scheme not only uses blind signature technology to provide internal privacy for centralized currency mixing, but also achieves forward security through signature key update, which can prevent adaptive attacks. In addition, through the security analysis and performance evaluation, the safety and effectiveness of the scheme are illustrated.