A Lightweight Fine-Grained Access Control Scheme with Forward Security for Mobile Crowdsourcing

As a service model that leverages large-scale terminal users on mobile devices to collaboratively complete tasks, mobile crowdsourcing services have significant advantages in promoting distributed collaboration and improving task completion efficiency. However, they also present challenges such as task privacy, task assignment and scheduling, and fine-grained access control. The existing cryptographic schemes for mobile crowdsourcing services have not adequately addressed these issues. Therefore, this paper proposes a forward secure attribute-based keyword search scheme tailored for mobile crowdsourcing services, effectively achieving fine-grained access control, fine-grained ciphertext retrieval, forward security, and data outsourcing confidentiality. Security analysis demonstrates that the scheme can withstand the chosen plaintext attacks and also satisfies index privacy and trapdoor unlinkability. Theoretical comparisons and simulation results confirm that the proposed scheme exhibits superior practicality and efficiency compared to related approaches, making it well-suited for mobile crowdsourcing services.