Research On Attribute-Based Encryption And Application In Email System

With the development of the information and internettechnology, the system security and functional design requirements continue to increase for the people. Because traditional public key encryption structure existscoarse-grained access control policies, and low efficiency, it is difficult to apply fine-grained access control policies ciphertext management. This papercentres on the research of the atrribute-based encryption (ABE)structure which has a fine-grained access control policies, and optimizes its performance. On this basis, the ABE program can be used in e-mail system, so that can be insure safety features with confidentiality and integrity, and in the functional design it has constantcomputational complexityfor a single and group e-mails encryption operation. This main works and results of this paper are as follows:On the research of attribute-based encryption structure, since ciphertext policy attribute-based encryption (CP-ABE) has the ciphertext fine-grained access control features, we focuses on its conduct research. For the original CP-ABE performance issues, we study the types of bilinear pairing with the performance of different types, and propose a new CP-ABE scheme based on asymmetric bilinear group. Then we define the notions of access structure, threshold and access tree structure, and claim the security model.of CP-ABE. Further, we optimize and improve CP-ABE decryption algorithm performance, such that it has a more efficient in the decryption algorithms.On the design of CP-ABE-based e-mail system, the traditional e-mail system has the integrity and confidentiality issues, and existing encrypted e-mail system existscomputation of low performance problem. Thus we first studied the principle of e-mail system; secondly for the current e-mail system problems, we analyze the system's design goals; then study and propose architecture of the e-mail system based on CP-ABE scheme which our proposed, give the core of our e-mail system functions, including system initialization, the applyingand issuing of secret key, sending and encryptionof e-mail, receivingand decryptionof e-mail.On the implementationof CP-ABE-based e-mail prototype system, based on the above research work, we first define core classes of CP-ABE-based secure e-mail system; then we give the system realization methodsand processesof each function; Finally, based onthe design and implementation of CP-ABE-based secure e-mail system,we test and verify the functions of our prototype system.whensending group e-mails, our prototype system g algorithm complexity O(1).