Design And Implementation Of Secret File Transmission System Based On PKI

The development of the computer application software contributed greatly to the process of office automation. Information delivery, shared with the collection and office electronic closely together. More and more government agencies, companies and individuals adopt office systems, such as Microsoft Office, and delivery documents through electronic document systems. So exploring the ways to protect the security of electronic documents has become increasingly urgent. The research on secure electronic document transmission system possesses great practical significance.The document mainly focus on a substantial research about the knowledge involved in the files secret system, such as basic encryption algorithm, basic cryptography, PKI system, as well as open-source OpenSSL library, while concentrating on the design and realization of the files secret system . And the main research results are as follows:1. A complete set of interaction protocols between the client and the server, Simple Files Secret Interacting Protocol, are proposed with the CS structure designing system to support the design and realization of the files secret system.2. The development of this system is based on the PKI system, the digital envelope distribution protocol and the USBKey personal certification mechanism. It not only achieves the function that document encryption and decryption is only supported for individuals in this system, which improves the security, but also provides the convenience for the document transportation and the use of the encryption and decryption function, which is better that similar products on market.3. It fully integrates the advantages of symmetric cryptography system with that of asymmetric cryptography system, and uses the technology of digital signature to provide the integrity and authenticity of encrypted files, which strengthens the protection of documents.