Briefing
Managing granular access rights and dynamic revocation in encrypted data systems, particularly for sensitive information like Electronic Health Records, remains a significant challenge for existing cryptographic schemes. This research introduces Inner-product Functional Encryption with Fine-grained Revocation (IPFE-FR), a new primitive that enables selective function computation over encrypted data while supporting precise revocation of access rights and ensuring forward security. This advancement fundamentally enhances data privacy and control for dynamic, multi-user environments, paving the way for more secure and adaptable blockchain architectures in sensitive data management.
Context
Traditional Public Key Encryption (PKE) offers all-or-nothing data access, which is too rigid for complex, multi-stakeholder systems. Attribute-Based Encryption (ABE) provides some access control but typically lacks the ability for fine-grained function-specific revocation and dynamic updates to keys or ciphertexts, leaving a critical gap in managing evolving access permissions over time.
Analysis
The IPFE-FR scheme introduces a system where data is encrypted such that only specific mathematical functions can be computed on it by authorized users, without revealing the underlying data. Its core innovation lies in incorporating system version numbers into cryptographic keys and ciphertexts, enabling a group manager to revoke individual users’ function-specific access rights. When a revocation occurs, the system updates a global version number, and a cloud server, using a special update key, re-encrypts existing data to the new version. This ensures that previously issued keys for revoked users become invalid for both new and old data, providing forward security and preventing collusion by binding user and function keys.
Parameters
- Core Concept ∞ Inner-product Functional Encryption
- New System ∞ IPFE-FR Scheme
- Security Assumption ∞ Learning with Errors (LWE)
- Key Authors ∞ Yue Han, Jinguang Han, Liqun Chen, Chao Sun
- Revocation Type ∞ Fine-grained, Indirect
- Security Properties ∞ Forward Security, Collusion Resistance
- Application Domain ∞ Electronic Health Records (EHR)
Outlook
This IPFE-FR scheme establishes a robust foundation for secure and adaptable data sharing, particularly in regulated sectors like healthcare where stringent privacy and access control are paramount. Future research will likely focus on optimizing its efficiency by exploring alternative lattice-based assumptions, such as Ring Learning with Errors (RLWE), to reduce computational overhead. The scheme’s principles could also extend to other privacy-preserving computation paradigms, enabling dynamic access control in decentralized finance (DeFi) for confidential asset management or in supply chain logistics for selective data disclosure.
Verdict
The IPFE-FR scheme represents a pivotal advancement in cryptographic access control, offering unprecedented flexibility and security for dynamic data environments crucial to future decentralized applications.
Signal Acquired from ∞ arxiv.org
