Cloud computing has prompted interest in data outsourcing. Attribute-based encryption (ABE) enhances file access control in cloud storage. User revocation remains a key challenge. This article presents a ciphertext-policy ABE (CP-ABE) scheme for efficient user revocation in cloud storage. User groups manage revocation, reducing computation costs. The scheme resists collusion attacks and is secure under the Diffie-Hellman assumption. Experiments confirm low computation costs, making it suitable for resource-constrained devices.

• Attribute-based Encryption
• Cloud Computing
• Data Security