An anonymous broadcasting system with accountability based on group signatures

Abstract

Advanced anonymous communication schemes have been proposed to protect the privacy of network users, enabling them to communicate anonymously on the Internet. However, this can lead to the issue of misuse of anonymous communication. Most anonymous communication systems lack accountability mechanisms, allowing malicious users to engage in illegal activities on the network without facing consequences. This presents difficulties for maintaining social stability and promoting anonymous communication. To address these challenges, we develop an accountable anonymous broadcast system that combines group signatures and a secret-shared shuffle protocol. This system allows honest users to anonymously publish messages, while the identities of users who publish illegal messages will be exposed. We employ batch verification to reduce the time required for verifying group signatures, which in turn reduces system latency. Finally, we implement the system and conduct performance evaluations to demonstrate its practicality. Compared to previous accountable anonymity mechanisms, our system can directly trace and hold malicious users accountable without compromising the privacy of honest users.