An incognito endorsement framework for the enterprise grade blockchain

Abstract

The blockchain is a publicly verifiable, time-stamped, tamper-proof, and decentralized ledger. The use-case of blockchain spans cryptocurrency, supply chain management, the internet of things, distributed identity management, and more. The public and distributed nature of blockchain is an invasion of privacy for several applications. Also, the research challenges in the security and privacy of blockchain must be addressed to unravel the full capability of blockchain. Hyperledger Fabric is a popular consortium blockchain framework hosted by the Linux foundation. The permissioned nature is realized through the strong authentication and authorization guarantees it offers to the participating organizations. The framework provides exceptional security and privacy features to its network participants. One such salient privacy feature is client anonymization rendered in Fabric through a cryptographic protocol suite called identity mixer or idemix for short. The idemix implementation provides privacy-preserving authentication, ensuring anonymity and unlinkability to the clients. It achieves the anonymity of clients by concealing its identity. And when several transactions are initiated by the same client it makes it infeasible to track that it was made by a single client thereby assuring unlinkability. A major limitation of the idemix membership service provider is that peers cannot sign using it; in other words, the privacy-preserving endorsement is not supported. In this dissertation, a privacy-preserving endorsement framework for Hyperledger Fabric is proposed through existing and proposed cryptographic artifacts. newline