Research And Design Of Hardware Structure For USB Cipher Card

Cipher Card is a hardware module based on bus interface of computer and offering cryptogram service function. Cipher Card can offer cryptogram service to PC system and network security device to realize safe storage for files and secure communication for information on network.With the fast development of USB technology , USB interface is used widely in field of PC and embedded system with its numerous superiorities of veriest plug and play, high transfers speed, especially after USB2.0 standard. In allusion to numerous excellences of USB, this paper provides a implementing scheme of hardware encryption device based on USB interface, and design a USB Cipher Card with high flexibility and strong security by integrating cryptogram technology and FPGA technology.This USB Cipher Card adopts USB2.0 standard, and adopts FPGA design technology, and imports embedded USB host technology. The Cipher Card can realize fast communication with host, and has fast cryptological operation ability, and offers update ability for arithmetic and hardware structure. The Cipher Card supports dispersed storage and online reconfiguration for arithmetics and keys, and offers digital physical noise circuit and can generate veriest random data , and it provides USB host interface to external and supports the mode of safe initialization by itself based on USB carrier ,and supports the method of identity authentication based on USB carrier. The Cipher Card can be used to any computer with USB interface, furthermore, its fixing is simple and its use is convenient.Firstly, this thesis researches the correlative design technology of USB Cipher Card. Secondly, it provides the whole goal and design ideas for USB Cipher Card, and researches and designs the whole hardware structure of USB Cipher Card ,and detailedly describes the design of hardware circuits of USB Cipher Card. Afterwards, we implement a few of functions by designing firmware modules based on the hardware. Finally, we realize the encrypting function based on FPGA, and test and analyse the whole encrypting performance of USB Cipher Card.