Design And Implementation Of Secure File Transfer System Based On Chaotic-DES Algorithm

The Internet is a media which is open but not secure. Its availability and powerfully computing and communications capabilities make it possible to form a new information exchange or even a new business mode, such as E-mail, file transfer, Telnet, Web page or business transactions.Over an insecure medium for transactions, it is easy to make confidential information leaked out and stolen. To protect users from Internet-based attacks, some measures such as password technology should be taken. As a result, a secure file transfer system based on chaos theory is designed and implemented, which uses the new chaos cryptography. The System is the one that is based on the TCP transport and combined with traditional password and chaos and taken a chaotic-DES of block encryption algorithm and based on Internet.The article is as follows:(1) Basic chaos theory is studied, including definition of chaos, motion characteristic and criterion. On this basis, with basic knowledge of cryptography, summed up the chaotic relationship with cryptography, all these laid the foundation for the new research area of chaos cryptography.(2) For the good performance of chaotic binary sequences, a new chaos system was come up. Then basic dynamic analysis is taken, including symmetry, dissipation, stability, Lyapunov index map and bifurcation diagram. On this basis, taken the chaotic system into discretization,combined with the DSP Builder tool, then a chaotic sequence generator can be realized on the FPGA,throngh D/A conversion, then the way to observe the oscilloscope waveform is used to judge whether the waveform still contain the original chaos properties.(3) After the chaotic system realizes digitalization, NIST standard is used to test sequences performance, by15indicators statistics to judge whether chaotic sequences meet the requirements of randomness.(4)In this article of the transport system, design and implementation of a hybrid algorithm for chaotic-DES. Combined Chaos theory and DES, but DES algorithm complexity retained, which call the design with "a set of key ". The RSA algorithm is used to encrypt chaotic initial value and its digital signature technology are also applied to verify in this system. As a result, three layers of protective film are applied into the entire system.(5)Design and implementation of a file transfer system based on chaos-DES. The system is designed on the J2SE platform, which uses MyEclipse tools to debug; take database technology to manage user information and key; apply the TCP protocols for file transfer. File transfer technology use the TCP transmission. JAVA Swing technologies are used to design interface. A function of the entire system is tested to verify its security and reliability. Finally, the algorithm’s key space, the sensitivity and efficiency of algorithms are studied and analyzed.Test results and theoretical analysis indicate that the system has some practical value.