PAChain: Private, authenticated & auditable consortium blockchain and its implementation

Abstract Blockchain provides a distributed ledger recording a globally agreed, immutable transaction history, which may not be suitable for Fintech applications that process sensitive information. This paper aims to solve three important problems for practical blockchain applications: privacy, authentication and auditability. Private transaction means that the transaction can be validated without revealing the transaction details, such as the identity of the transacting parties and the transaction amount. Auditable transaction means that the complete transaction details can be revealed by auditors or law enforcement agencies. Authenticated transaction means that only authorized parties can be involved in the transaction. Auditability prevents a malicious user from abusing the privacy property. Authenticity helps the auditor to trace the identity of the malicious user in the system. In this paper, we present a private, authenticated and auditable consortium blockchain, using a number of cryptographic building blocks. Our scheme can be integrated with the architecture of consortium blockchain. 1