A Blockchain-Based Secure Data Sharing Mechanism in Crowdsourcing Using Continuous Leakage-Resilient Identity-Based Encryption

Crowdsourcing technology utilizes mobile sensing devices as basic sensing units to accomplish task allocation and data collection. Currently, it has emerged as a novel approach for addressing large-scale and intricate tasks. However, the collected sensing data often contain valuable information, necessitating careful consideration of data privacy. Traditional data privacy protection schemes are predominantly centralized, which makes them susceptible to single-point failures, trust crises, and scalability issues. Simultaneously, these traditional schemes fail to account for the risk of key leakage resulting from side-channel attacks within real network environments. Therefore, a distributed and leakage-resilient privacy protection mechanism has great practical value in crowdsourcing applications. To this end, we propose a blockchain-based secure data sharing mechanism for crowdsourcing applications. Our main contribution is to propose an identity-based encryption (IBE) scheme that achieves continuous leakage-resilient security. From the adversary's perspective, the ciphertext structure in the scheme appears entirely random, making it infeasible to extract private key information. We establish the proposed scheme's CCA security under the selective-ID model, relying on the decisional l-wBDHI* assumption. Theoretical analysis validate the scheme's advantages, feasibility, and effectiveness.