Research On Efficient Id-Based And Bilinear Pairings Based Generalized Signcryption

Generalized signcryption can resolve the problem which identity-based signcryption must turn to other signature or encryption algorithm when only one of confidentiality or authenticity functionalities is required. Identity-based generalized signcryption scheme can be used as a signcryption scheme, as an encryption scheme and as a signature scheme as per requirement. They termed the new primitive as generalized signcryption. This paper will proposed two new more efficient identity-based generalized signcryption scheme.Firstly, we studied the existing generalized signcryption scheme, and by doing in-depth research and analysis on the existing schemes, we worked out the reasons which make identity-based generalized signcryption scheme less effient are too much bilinear pairings are used.Secondly, we proposed one identity-based generalized signcryption scheme. By studing predecessors'schemes, absorbbing their advantages and improving their shortings, we proposed a new identity-based generalized signcryption scheme using the bilinear pairings and the ideas of gernalization. And we demonstrated the security, unforgeability and non-repudiation. Specially, we demonstrated the confidentiality under the Random Oracle model. We analyzed the efficiency of the scheme by comparing with the existing scheme.Finally, we proposed an identity-based generalized signcryption scheme without trusted PKG using the bilinear pairings and the ideas of gernalization. The proposed scheme can avoid"key escrow"problem. we demonstrated the basic security needed. And we analyzed the efficiency of the scheme by comparing with the existing scheme.