[論文レビュー] SoK: Self-Sovereign Digital Identities

Sushanth Ambati, Kainat Adeel+2 more|arXiv (Cornell University)|Mar 6, 2026

Cryptography and Data Security被引用数 0

ひとこと要約

このSoKはSelf-Sovereign Digital Identities（SSDI）の実世界採用を妨げる課題を体系的に整理し、文献と展開を分析し、今後の研究方向を概説します。

ABSTRACT

Self-Sovereign Digital Identity (SSDI) enables individuals to control their own identity assertions and data, rather than relying on centralized or federated systems prone to large-scale data breaches. By eliminating centralized databases maintained by service providers and identity brokers, SSDIs offer enhanced security and privacy. However, adoption remains slow, and research in this area lacks systematization and uniformity. To address these gaps, we present a comprehensive systematization of knowledge on self-sovereign digital identities, with a primary focus on identifying the challenges that impede real-world adoption. We survey 80 academic and non-academic sources and identify six major challenges: (i) binding a single identity to one individual or organization, (ii) the absence of mature cryptographic and communication protocols, (iii) significant usability barriers, (iv) regulatory and oversight gaps, (v) bootstrapping to critical-mass adoption, and (vi) dependence on a permissionless, decentralized, yet singular infrastructure that may expose unforeseen vulnerabilities over time. We then analyze 47 scientific publications and find that the vast majority focus on blockchain-based solutions rather than generalized SSDI architectures. Additionally, we catalog 12 real-world, production-grade SSDI applications. Our evaluation of these solutions reveals that self-sovereignty is, in practice, a spectrum rather than a binary property. Finally, we explore the frontiers of SSDI by identifying major trends, open problems, and opportunities for future research. We hope this systematization will help advance the shift from centralized to self-sovereign digital identities in a disciplined and impactful way.

研究の動機と目的

• Identify and articulate the fundamental challenges hindering SSDI adoption.
• Survey existing surveys and literature to understand the current state and gaps.
• Evaluate production SSDI solutions to assess how self-sovereignty manifests in practice.
• Provide a research roadmap highlighting technologies, governance, and standardization needs.
• Highlight frontiers and opportunities for advancing SSDI in practice and policy.

提案手法

• Review 80 diverse sources including academic papers, industry reports, standards bodies, and grassroots initiatives to derive a challenge taxonomy.
• Conduct a structured review of 47 scientific publications to classify trust infrastructures, cryptographic techniques, and evaluation methods.
• Assess 12 production-grade SSDI deployments along five self-sovereignty dimensions: user control of keys, absence of a gatekeeper for issuance, credential portability, selective disclosure, and resistance to unilateral revocation.
• Analyze the literature’s focus, revealing a blockchain bias and underexplored generalized SSDI architectures.
• Outline a forward-looking research roadmap addressing technical, regulatory, and adoption-related frontiers.

実験結果

リサーチクエスチョン

• RQ1 What are the core barriers preventing widespread adoption of SSDI in practice?
• RQ2 How does the current scientific literature characterize trust models, cryptography, and evaluation methods in SSDI systems?
• RQ3 What is the state of real-world SSDI deployments, and how self-sovereignty is expressed across these implementations?
• RQ4 What directions and standards are needed to advance SSDI research and practical adoption?

主な発見

• Six fundamental challenges hindering SSDI adoption: identity binding, key management and protocols, usability, oversight and regulation, critical-mass adoption, and single infrastructure dependence.
• Scholarly work is dominated by blockchain-focused solutions (83% on a blockchain platform), with limited exploration of generalized SSDI architectures.
• Real-world SSDI deployments exist but show sovereignty as a spectrum rather than a binary property.
• Evaluation of literature shows a heavy emphasis on protocols and key management, with relatively few formal security proofs or user studies.
• The paper provides a research roadmap highlighting zero-knowledge proofs, homomorphic encryption, regulatory harmonization, and Web3 integration as key frontiers.