Fairly verifiable multi-user homomorphic proxy re-encryption scheme

To address the challenges of multi-user ciphertext sharing and secure fair computation in untrusted cloud environments where traditional fully homomorphic encryption algorithms prove inadequate, a verifiable identity-based multi-user homomorphic proxy re-encryption scheme was proposed. Firstly, a non-cooperative game model was constructed, and a dynamic resource allocation algorithm was proposed to achieve fair resource distribution for third-party cloud servers, ensuring fairness and efficiency in resource utilization. Secondly, ciphertext conversion was implemented through proxy re-encryption technology to support multi-user homomorphic computation and meet fine-grained ciphertext sharing requirements. Finally, an authorized function-based homomorphic signature was employed to verify computation results and cloud server behaviors, with security proofs of the proposed scheme was provided under the standard model. Theoretical analysis and experimental results demonstrate that the proposed scheme exhibits re-encryption verifiability and enables multi-user homomorphic computation.