Improving the proof of "Privacy-preserving attribute-keyword based data publish-subscribe service on cloud platforms"

Area of Science:

• Cryptography
• Cloud Computing Security
• Data Privacy

Background:

• Attribute-keyword based encryption (AKPS) is crucial for secure data sharing in cloud storage.
• The original AKPS scheme by Kan Yang et al. has a security flaw in its proof of indistinguishability against chosen keyword attacks under the Bilinear Diffie-Hellman (BDH) assumption.

Purpose of the Study:

• To identify and rectify the security flaw in the AKPS scheme's security proof.
• To provide a more rigorous security proof for the AKPS scheme.
• To evaluate the AKPS scheme's resilience against Replayable Chosen Ciphertext Attacks (RCCA).

Main Methods:

• The study re-examines the security proof of the AKPS scheme.
• A new security proof for indistinguishability is developed based on the Decisional Diffie-Hellman (DDH) assumption.
• The scheme's security against Replayable Chosen Ciphertext Attacks (RCCA) is formally demonstrated.

Main Results:

• A flaw in the original security proof of indistinguishability against chosen keyword attacks was identified.
• An improved and more rigorous security proof for indistinguishability, based on the DDH assumption, was successfully constructed.
• The AKPS scheme was proven to be secure against Replayable Chosen Ciphertext Attacks (RCCA).

Conclusions:

• The original security proof for the AKPS scheme contains a critical flaw.
• The proposed enhanced security proof provides a more robust foundation for the AKPS scheme's security.
• The AKPS scheme, with the improved proof, offers enhanced security for cloud storage data publish-subscribe services.