Resettable Zero-Knowledge in the Weak Public-Key Model

A new public-key model for resettable zero-knowledge (rZK) protocols, which is an extension and generalization of the upper-bounded public-key (UPK) model introduced by Micali and Reyzin [EuroCrypt’01, pp. 373-393], is introduced and is named weak public-key (WPK) model. The motivations and applications of the WPK model are justified in the distributed smart-card/server setting and it seems more preferable in practice, especially in E-commerce over Internet. In this WPK model a 3-round (optimal) black-box resettable zero-knowledge argument with concurrent soundness for NP is presented assuming the security of RSA with large exponents against subexponential-time adversaries. Our result improves Micali and Reyzin’s result of resettable zero-knowledge argument with concurrent soundness for NP in the UPK model. Note that although Micali and Reyzin’ protocol satisfies concurrent soundness in the UPK model, but it does not satisfy even sequential soundness in our WPK model. Our proto...

• Type: Conference
• Year: 2003
• Where: EUROCRYPT
• Authors: Yunlei Zhao, Xiaotie Deng, Chan H. Lee, Hong Zhu
• Keywords: Concurrent Soundness, Cryptography, EUROCRYPT 2003, Resettable Zero-knowledge Argument, WPK Model