Complex Conjugated certificateless-based signcryption with differential integrated factor for secured message communication in mobile network

Certificateless-based signcryption overcomes inherent shortcomings in traditional Public Key Infrastructure (PKI) and Key Escrow problem. It imparts efficient methods to design PKIs with public verifiability and cipher text authenticity with minimum dependency. As a classic primitive in public key cryptography, signcryption performs validity of cipher text without decryption by combining authentication, confidentiality, public verifiability and cipher text authenticity much more efficiently than the traditional approach. In this paper, we first define a security model for certificateless-based signcryption called, Complex Conjugate Differential Integrated Factor (CC-DIF) scheme by introducing complex conjugates through introduction of the security parameter and improving secured message distribution rate. However, both partial private key and secret value changes with respect to time. To overcome this weakness, a new certificateless-based signcryption scheme is proposed by setting the private key through Differential (Diff) Equation using an Integration Factor (DiffEIF), minimizing computational cost and communication overhead. The scheme is therefore said to be proven secure (i.e. improving the secured message distributing rate) against certificateless access control and signcryption-based scheme. In addition, compared with the three other existing schemes, the CC-DIF scheme has the least computational cost and communication overhead for secured message communication in mobile network.

基于无证书签密（certificateless-based signcryption）克服了传统公钥基础设施（Public Key Infrastructure，PKI）的固有缺陷与密钥托管问题（Key Escrow problem）。该方案提供了高效的构建路径，可设计具备公开可验证性与密文真实性、且依赖度极低的公钥基础设施。作为公钥密码学中的经典原语，签密（signcryption）通过将认证、机密性、公开可验证性与密文真实性相结合，无需解密即可完成密文有效性验证，其效率远优于传统方案。本文首先针对无证书签密构建安全模型，通过引入安全参数、提升安全消息分发速率并引入复共轭（complex conjugates），提出了复共轭差分积分因子（Complex Conjugate Differential Integrated Factor，CC-DIF）方案。然而该方案中，部分私钥与秘密值均随时间动态变化，为克服这一缺陷，本文通过利用积分因子（Integration Factor）构建微分方程（Differential Equation，Diff）来设定私钥，提出了一种新型无证书签密方案，该方案有效降低了计算开销与通信开销。因此，该方案被证明可在无证书访问控制与基于签密的方案场景下具备安全性（即提升安全消息分发速率）。此外，相较于其他三种现有方案，CC-DIF方案在移动网络的安全消息通信场景下，拥有最低的计算开销与通信开销。