Certificateless threshold signcryption scheme with secret sharing mechanism

摘要

A (t,n) threshold signcryption scheme makes the distributor authorize a group with n members, any t or more signcrypters can cooperatively use the signcryption keys to sign the message; however, t−1 or fewer signcrypters cannot. Threshold signcryption has broad applications in the electronic auction, electronic election, distributed environment, cloud computing and block chain. In this paper, we combine the threshold signcryption with certificateless cryptosystem to construct a secure and efficient certificateless threshold signcrypton scheme with secret sharing mechanism (SSM-CLTSCS), which is provably indistinguishable and unforgeable under the hardness of the DBDH (decisional bilinear Diffie–Hellman) and CDH (computational Diffie–Hellman) problems. Analysis shows SSM-CLTSCS outperforms the existing schemes in computational efficiency; and so it will obtain much more attention in the application fields of information security.