EVOAC-HP: An Efficient and Verifiable Outsourced Access Control Scheme with Hidden Policy

Area of Science:

• Computer Science
• Information Security
• Healthcare Informatics

Background:

• Medical data security is paramount, requiring robust access control.
• Existing Ciphertext-Policy Attribute-Based Encryption (CP-ABE) schemes face challenges with computational decryption costs and potential user privacy disclosure.
• Large-scale medical data sharing necessitates efficient and secure access control solutions.

Purpose of the Study:

• To design an improved CP-ABE scheme for efficient and verifiable outsourced access control with fully hidden policies.
• To address the computational decryption burden on resource-limited users.
• To enhance user privacy by hiding access policies and preventing attribute leakage.

Main Methods:

• Developed EVOAC-HP, an enhanced CP-ABE scheme.
• Utilized attribute bloom filters for policy hiding and user privacy preservation.
• Implemented outsourced decryption via a Cloud Service Provider (CSP) to reduce user-side computation.
• Ensured verifiability of transformed ciphertexts by data users.

Main Results:

• EVOAC-HP achieves fully hidden access policies using attribute bloom filters.
• Outsourced decryption significantly reduces the computational load for data users.
• The scheme provides verifiable outsourced decryption, ensuring data integrity.
• Rigorous analysis confirms the scheme's practicality, effectiveness, and robust privacy protection.

Conclusions:

• EVOAC-HP offers a practical and effective solution for secure and private medical data sharing.
• The proposed scheme enhances usability for resource-limited users through outsourced decryption.
• Attribute bloom filters effectively hide access policies, bolstering user privacy in healthcare data sharing.