A Survey of Blockchain-Based Privacy Applications: An Analysis of Consent Management and Self-Sovereign Identity Approaches

TL;DR

This survey reviews blockchain-based privacy solutions focusing on consent management and self-sovereign identity, highlighting current tools, challenges, and future research directions in privacy-preserving distributed applications.

Contribution

It provides a comprehensive analysis of existing blockchain privacy approaches, emphasizing consent and identity management, and identifies open challenges and research opportunities.

Findings

Blockchain enhances transparency but lacks inherent privacy support.

Cryptographic schemes and consent mechanisms are crucial for privacy.

Open challenges include scalability, interoperability, and user control.

Abstract

Modern distributed applications in healthcare, supply chain, and the Internet of Things handle a large amount of data in a diverse application setting with multiple stakeholders. Such applications leverage advanced artificial intelligence (AI) and machine learning algorithms to automate business processes. The proliferation of modern AI technologies increases the data demand. However, real-world networks often include private and sensitive information of businesses, users, and other organizations. Emerging data-protection regulations such as the General Data Protection Regulation (GDPR) and the California Consumer Privacy Act (CCPA) introduce policies around collecting, storing, and managing digital data. While Blockchain technology offers transparency, auditability, and immutability for multi-stakeholder applications, it lacks inherent support for privacy. Typically, privacy support is added to a blockchain-based application by incorporating cryptographic schemes, consent mechanisms, and self-sovereign identity. This article surveys the literature on blockchain-based privacy-preserving systems and identifies the tools for protecting privacy. Besides, consent mechanisms and identity management in the context of blockchain-based systems are also analyzed. The article concludes by highlighting the list of open challenges and further research opportunities.