A Ciphertext-Policy Attribute-Based Signcryption Scheme

Signcryption can simultaneously fulfil both the functions of digital signature and public key encryption in a logically single step,and with a cost significantly lower than that required by the traditional signature-thenencryption approach.In order to satisfy only a group with some attributes that can decrypt the sensitive message and verify signatures,a new ciphertext-policy attribute-based signcryption scheme was proposed.This scheme not only provides secrecy and authenticity simultaneously,but also can control the user's ability to decrypt by the access structure.Unlike similar schemes,our scheme can realize classification decryption,and different users will acquire different information from the same ciphertext.