A keyword searchable attribute-based encryption scheme with attribute update for cloud storage.

Area of Science:

• Cryptography and Information Security
• Cloud Computing Security

Background:

• Ciphertext-policy attribute-based encryption (CP-ABE) offers fine-grained access control for cloud data.
• Keyword-based searchable encryption enables efficient, private data retrieval from cloud servers.

Purpose of the Study:

• To develop a CP-ABE scheme that integrates keyword search functionality.
• To enable efficient attribute updates for users in a cloud storage environment.
• To enhance security and reduce computational burden for users.

Main Methods:

• Combined CP-ABE with keyword searchable encryption.
• Implemented an efficient attribute update mechanism requiring only secret key updates.
• Outsourced computationally intensive operations to the cloud server.

Main Results:

• The proposed scheme supports attribute updates without re-encrypting data or updating other users' keys.
• Reduced computational overhead for individual users.
• Achieved proven semantic security against chosen ciphertext-policy and chosen plaintext attacks.
• Demonstrated semantic security against chosen keyword attack under the BDH assumption.

Conclusions:

• The developed scheme provides a secure and efficient solution for keyword searchable attribute-based encryption in cloud storage.
• Attribute updates are handled effectively, minimizing disruption and computational cost.
• The scheme offers robust security guarantees against various attack models.