Privacy-Preserving Block-chain Framework Based on Ring Signatures (RSs) and Zero-Knowledge Proofs(ZKPs)

Abstract

Block-chain emerged as the technology of choice for most applications because of its immutability property. Block-chain's immutability property promotes network resilience against any removal or modification of data stored on the ledger. However, large scale networks such as the Internet of Things (IoT) that may contain millions of nodes can significantly increase Block-chain size and raise serious privacy challenges. Moreover, the General Data Protection Regulations (GDPRs) that were enforced in May 2018 by European countries allows individuals and organizations to take control of their data by establishing stringent rules which includes “the right to be forgotten”. In cases where there are ethical or legal reasons individuals and companies might want their personal data stored to be erased whether such data is stored locally or on the ledger. The philosophy underpinning Block-chains is that forcing nodes to erase data is akin to denying them a role to play in the Block-chain ecosystems as full nodes. In this paper, we attempt to challenge this notion by proposing a model framework for an enhanced privacy that is akin to Block-chain erasure. Our approaches combine ring signatures (that have long been used to generate anonymous signatures) and Zero-Knowledge Proofs (ZKPs) that can help to disguise user's wallet addresses.