Design And Research Of Identity Authentication Protocols Based On Computational Ghost Imaging

Identity authentication is the process of verification that an individual or an entity is who it claims to be. In recent years, information technology has been highly developed. As the first line of defense in information security system, identity authentication is the most important one. The traditional identity authentication techniques mainly depend on the computer, digital signal processor and other electronic devices. However, the speed and cost of hardware will limit their applications. It becomes an urgent need to develop more efficient and more secure information technology.Optical identity authentication technology has drawn more and more attention due to its fast operating speed, realization of multidimensional information and other advantages."Ghost" imaging is a kind of interesting optical phenomenon, which gets image of an object with coincidence measurement from idler beam and signal ones. Computational "ghost" imaging technology is an improved method of the traditional "ghost" imaging. With the help of spatial light modulators (SLMs), it can modulate light. As the information of SLMs can be as keys in secure communication,"ghost" imaging technology has been used to identity authentication.In this paper, we first simulate computational "ghost" imaging. The corresponding imaging quality is charactered by the mutual information and the peak-background rate of the nonlinear correlation between image and original object. Results show that at least100percents of sampling rate is needed to guarantee good imaging quality. The goal of identity authentication is not to get high fidelity image, so sampling rate is not necessarily high. We then present two identity authentication protocols based on the computational "ghost" imaging. The first authentication method uses N random phase masks generated by SLMs as a key to encrypt the original object, and nonlinear correlation algorithm is used to authenticate the decrypted object. Based on this, we propose a multi-user authentication system. Simulation results show that, in the authentication process, the sampling rate and peak-background threshold of the nonlinear correlation are relatively lower than that for comparing to imaging. The sampling rate is4.88%and the peak-background threshold is8in our cases. The second protocol is based on a multiple-key mechanism. A number of different distances between SLMs and the original object are set, which are another keys. In traditional, there is only one distances in the ordinary computational "ghost" imaging. The nonlinear correlation algorithm is also used, which has been used in the first protocol. Simulation results show that it has higher security because the multiple-key mechanism is applied.