# RFID Authentication System Based on User Biometric Information +
###### 1 Introduction  
With the rapid development of modern technology, new automatic identification technologies emerge in endlessly, among which radio frequency identification (RFID) technology has become the core technology of the Internet of Things with its excellent advantages. With the commercialization of RFID, its application is becoming more and more widespread, including item tracking, motion detection [1, 2], goods security and so on [3, 4, 5, 6, 7]. As the increasing demand on protection for security industry and personal privacy, user authentication technology has become particularly important. The purpose of user authentication is to verify whether a user is indeed a legitimate user registered in the system, which is a vital task in many applications, such as area or event access control and electronic payment. In the existing work, user authentication methods are mainly divided into two categories: device authentication and user authentication. Authentication devices such as personal identity cards, authentication users such as fingerprints, etc. ; both authentication technologies are each facing many potential risks and hidden dangers due to imperfect security mechanisms. Device authentication may have the risk of being lost, stolen, or copied. When users set their passwords too short or simple, their accounts can easily be stolen,leading to insecure accounts on other systems as well. If complex passwords consisting of numbers and letters are used alternately, it can increase the security strength of the password, but it will increase the complexity of the system usage and is very unfriendly to users. When the system uses ID cards to identify and verify user identity, the cards may be at risk of being copied or lost. As in the Hu-Fu ([PERSON] et al. [8; 9]) authentication scheme, if the authentication tag is stolen by an attacker, the attacker can pass the authentication without any hindrance; with RF-Mehndi ([PERSON] et al. [10]), although the personal card is also able to resist the attacker's counterfeit when it is lost or stolen, the user card needs to be recreated and the information collected will still cause trouble to the user. User authentication-based schemes to verify users' biological information, such as Vauth ([PERSON] et al. [11]), Cardiac Scan ([PERSON] et al. [12]), BioTag ([PERSON] et al. [13]. ), and TrueHeart ([PERSON] et al. [14]) continuous authentication schemes, mostly require the use of dedicated sensors, which have major limitations in terms of cost and applicability. While the mainstream user authentication methods now use biometric features such as the user's fingerprint, face ([PERSON] et al. [15]), and iris to authenticate the user's identity, biometric features such as fingerprints provide a more excellent authentication performance compared to traditional authentication techniques. However, it is by nature a static image or data matching and still has the possibility of being copied. To overcome these problems, cutting-edge research has proposed a concept of continuous authentication, i.e., using some device to continuously extract dynamic human biometric features for authentication, such as breathing ([PERSON] et al. [16]), heart rate ([PERSON] et al. [14]), and sound resonance ([PERSON] et al. [11]). However, continuous authentication requires a very high acquisition rate and computational power of the device, leading to excessive cost and difficulty, and it can still only be implemented in an experimental setting. In summary, although many user authentication methods have been proposed [5; 8; 9; 10], they have some contradictions and drawbacks in terms of application target, deployment scope, cost, system complexity, and security resistance. It is a new challenge to find a simple and secure authentication method.