Research And Implementation On Identity-based Authentication Cryptosystems

Public-key cryptography is a new direction which borders the platform of cryptography research. User's identity and public key are stored in a certificate on the condition of the traditional public-key cryptography which needs additional management to the certificate and aggravates the burden of system.The identity based cryptosystem using user's identity as public key simplifies the certificate management. Until now all kinds of identity based schemes have been released. In the Identity-based signature scheme, the KGC(Key Generate Center) provides each user with the private key which results in its inherent security risk: key escrow problem.We solve the key escrow problem by proposing a multi-key management scheme which ensures the authentication for users and protects against the creadible crisis of KGC or KPA(Key Privacy Authority). But the security of the privacy keys can not be guaranteed when the collusion of KGC and KPAs. In the advanced scheme, each user chooses a long-term private key to prevent the collusion of KGC and KPAs.We combine authentication and encryption to obtain an Identity-based authenticated encryption scheme which also guarantees the confidentiality of the data. A symmetric cryptography algorithm is used to ensure the data privacy, and the key only can be calculated by sender and receiver. Access control aims to limit the access to system, and RBAC(Role-Based Access Control) is an important aspect. We propose IRBAC(Identity Role-Based Access Control)model which combines Identity-Based cryptography with RBAC to ensure the confidentiality of data as well as the authentication of users.Basing on IRBAC model, implement authenticated encryption scheme.