Weighted Attribute-Based Proxy Re-Encryption Scheme with Distributed Multi-Authority Attributes.

Area of Science:

• Cloud Computing Security
• Cryptography
• Data Sharing

Background:

• Existing attribute-based proxy re-encryption schemes face challenges with complex access policies, significant ciphertext storage, and centralized authority, compromising secure cloud data sharing.
• These limitations result in weak security and reduced controllability over shared data in cloud storage environments.

Purpose of the Study:

• To propose a novel Weighted Attribute Authority Multi-Authority Proxy Re-Encryption (WAMA-PRE) scheme.
• To address the limitations of existing schemes by simplifying access policies, reducing ciphertext storage, and decentralizing authority for enhanced cloud data security.

Main Methods:

• Introduced attribute weights to enable multi-valued access policies, moving beyond binary expressions.
• Implemented a multi-authority system where multiple attribute authorities and a central authorization entity jointly construct a key.
• Developed a distributed attribute authority network to bolster cloud storage's resistance to attacks.

Main Results:

• Attribute weighting reduced ciphertext storage space by 50%.
• Proxy re-encryption achieved a 63% time saving compared to re-encryption.
• Joint key construction time was only 1% of the benchmark scheme.
• The WAMA-PRE scheme demonstrated CPA security under the decisional q-parallel BDHE assumption.

Conclusions:

• The WAMA-PRE scheme offers a significant improvement over existing methods for secure data sharing in cloud storage.
• The proposed scheme enhances security, reduces storage overhead, and improves efficiency through simplified policies and distributed authority.
• WAMA-PRE provides a robust and effective solution for the challenges of secure data sharing in cloud environments.