A Provable Secure Identity-based Threshold Proxy Signcryption Scheme

Proxy signature can achieve the commission of the signature rights with authentication and non repudiation, but they cannot provide the confidentiality. Signcryption is a technology combined with encryption and signature, it also has the advantages of both. By using bilinear pairing technology this program propose an efficient identity-based threshold proxy signcryption scheme under the standard model and analyze the security of the scheme. Finally, we prove the semantic security of the scheme through the difficulty of DBDH problem, simultaneously, prove the unforgeability of the scheme through the difficulty of CDH problem.