Blockchain privacy: Fundamental aspects and challenges for the future Internet data sharing

Privacy concerns the majority of individuals, governments, and organizations that share data over dissimilar networks of nodes. Every kind of participant requires awareness of the data journey that unfolds inside a blockchain network with its own trustworthy rules of data management and accessibility. This paper provides a methodological approach on privacy for data sharing within blockchain environments. Specific technological aspects of blockchains that relate to on‐chain privacy such as network nature, party join, smart contracts, blockchain states, transactions, and ledger flows, are analysed with respect to the involvement and impact of privacy in distributed ledgers. A high‐level architectural approach is suggested that is intended to address significant privacy concerns on data sharing among different kinds of users in the context of blockchain networks deployment and the broader Web 3.0 ecosystem building. Simultaneously, many pertinent challenges are discussed regarding network nature, configurable privacy, ownership, confidentiality, secured computation, and data monetization that appear in the field and ought to be carefully tackled for the future mass adoption of privacy‐matured distributed ledgers that interconnect delivering the future Internet. This article presents significant blockchain aspects respecting privacy impact on data sharing. It argues on the essential mutual exclusivity between the blockchain properties of privacy and transparency and provides a high‐level architecture configuring data sharing privacy through states, transactions, and ledger flows. Finally, it concludes on current challenges concerning network nature, configurable privacy, ownership, confidentiality, secured computation, and data monetization.