Y Attrichain: Decentralized Traceable Anonymous Identities In Privacy-Preserving Permissioned Blockchain

In this paper, we propose a framework named AttriChain that supports transactions with anonymous sender identity and threshold traceability in permissioned blockchain. AttriChain realizes on-chain access control and distributed identity governance by allowing users to create transactions anonymously using their transaction keys and their attributes. It provides unlinkability and anonymity of transactions belonging to legitimate users whereas provides accountability for those whom other members in the network regard as questionable or malicious. The design of threshold traceability of anonymous transactions allows network members to trace transactions back to the sender without violating the decentralized property of blockchain. In AttriChain, the spontaneous tracing of misbehaviors in the network distributes the power of identity governance to multiple independent tracing members instead of depending on single -point management. It significantly increases user privacy and autonomy in a permissioned network and facilitates auditing at the same time. We define the functionality and the protocol of AttriChain in the universal composable model. We also provide an implementation of an AttriChain prototype for performance analysis. (C) 2020 Elsevier Ltd. All rights reserved.