Research And Implementation Of Security Protocol For USB Storage Devices

USB(Universal Serial Bus) is a universal external bus standard that standardizes the connection between peripherals and personal computers. With USB devices becoming more complex, transmission rate becoming faster, security issues of USB storage devices become a focus which are gradually paid more attention. Although researchers have proposed protocol for secure USB storage devices, there are still shortcomings. More comprehensive, efficient and secure authentication p rotocol need to be studied.This thesis enhances and achieves a more secure protocol of USB storage devices for the current USB attacks. The main contents are as follows:1. The security protocol of USB storage devices and encryption/decryption algorithm are studied. Meanwhile, the enhanced three- factor security protocol for USB storage devices are focused. Combining with the subject requirements, by analyzing the current USB attacks and precautions, this thesis points out the security risks of existing security protocol of USB storage devices.2. This thesis enhances the security protocol of USB storage device s, improves the security of the protocol, and reduces the complexity and computing cost of the protocol. Firstly, in order to ensure the safety of the initial channel and prevent the middle attack, a secure channel is established by using the initial key in key agreement stage. Secondly, the authentication server(AS) is used for identity authentication. Due to the device chip dose not store any informa tion relating to identity authentication, it can prevent attacks against the device chip. Thirdly, the enhanced protocol can work independently or combining with the hardware-based authentication. At the same time, the server program can extend functions, such as reporting loss, deleting remote files. So it has good function scalability and flexible application scenarios. Finally, the security assessment and compute cost of the enhanced protocol are analyzed and compared with the existing protocols.3. The implementation of enhanced security protocol of USB storage devices includes USB device, USB host and AS. The hardware of USB device is based on MSP430F5529, external Flash and other circuit. It implements bottom driver, encryption transmission and storage with MSD and HID. HID completes the encryption transmission of the file key to prevent eavesdropping attacks. With the concurrent threads, AS achieves task queue management, worker thread management and security protocol of server-side, and so on. USB host program mainly implements HID device enumeration, HID channel establishment and transmission, protocol implementation of client-side and other functions. Through the testing of security protocol system, the results show the efficiency of the improved protocol. At the same time, the system has made good performance and can meet the requirement of customer.