The Design And Implementation Of File Management System Under Heterogeneous Environment

Hulft is a system developed by the Sassion company in Japan, and it can transmit data and share files among platforms of different operating system and under heterogeneous network environment, which achieves virtualization of storage. It is convenient to operate files on different Resource-Machines like the operation on files of the local disks. The sales of Hulft system has been highest in the Japanese domestic market.The author's contributions in the development of project is design of system architecture and design of the process of TSSP, and implementation of TSSP between Resource-Machines (run on Windows) and the transfering station. Now, Hulft system of version 7.0 has passed the acceptance, and is used by customers.However, there are many shortcomings in Hulft system of old version 6.0. Firstly, the number of Resource-Machines connected to the process-center is limited by system architecture, so that the system is not expandable. Secondly, communication between Resource-Machines may cause failure of authentication. Thirdly, the classical Digital Time Stamp Protocol of SOAP adopted in Hulft 6.0 system has safety problem. If violations of TSA(Time Stamp issuing Authority) occur, or if TSA's signature private key is lost, security of classical Digital Time Stamp Protocol of SOAP is destroyed.To solve the problems in Hulft 6.0, the author proposed a new architecture and a protocol, named Time stamp protocol of SOAP based on Secondary digital signature (TSSP). The new system architecture can not only improve the scalability of the system, but also enhance the accuracy of authentication between Resource-Machines. TSSP can not only prevent violations from TSA, but also avoid threat from the lost of digital signature private key. The main idea is to monitor TSA when time stamp is issued, at this time TSA is required to leave undeniable evidence for other entities to inspect the authenticity of Time Stamp. Based on the classical Digital Time Stamp Protocol of SOAP, digital signature private key, SIG1,SIG2,SIG3......SIGn are added into TSSP to certify the authenticity of Time Stamp issued by TSA, and a function is defined to select one of the n digital signatures.The author has introduced the system architecture design of Hulft 7.0, and demonstrates working process of TSSP and the advantage of TSSP relatively compared to classical Digital Time Stamp Protocol of SOAP. The article introduces the implementation of TSSP in the Hulft 7.0 system. Results from protocol security test can certify that security vulnerabilities in classical Digital Time Stamp Protocol of SOAP disappears in TSSP. And results from system performance test on file copy, create, modify, delete, freshment, shows that the system can response successfully and run normally. At the same time, the paper also point out the expecting improvement in Hulft 8.0 system.