###### Abstract  
In recent years, Dedicated Short-Range Communication (DSRC) vehicle interconnection technology has achieved mature development and broad applications, which is the key Vehicle to Everything (V2X) technology to realize transport intelligence. However, the openness of wireless transmission and the mobility of wireless terminals cause the identification mechanism of the DSRC system to face serious security threats. A radio frequency fingerprint (RFF)-based identification method can better resist the identity attack and spoofing by extracting the hardware characteristics formed by the differences of electronic components to authenticate different devices. Therefore, in this paper a novel RFF identification mechanism is proposed for IEEE 802.11p protocol-based DSRC intelligent vehicle networking devices suitable for a high mobility environment, in which the preamble field features of physical layer frames are extracted as device fingerprints, and the random forest algorithm and sequential detection method are used to distinguish and authenticate different devices. The experiment and simulation results demonstrate that the identification accuracy rates of the eight DSRC modules in the low-speed LOS and NLOS experimental states and up to 70 km/h high-speed simulations all exceed 99%, illustrating that this method has important application value in the field of identity authentication of V2X devices in high-speed scenarios. vehicle networking; radio frequency fingerprint; feature extraction; device identification 20 April 2022 22 April 2022 22 April 2022 202  
wireless local area network protocol, while C-V2X is a cellular communication V2X standard technology based on 4G Long Term Evolution (LTE) and 5G New Radio (NR). C-V2X technology appeared slightly later than DSRC, whereas its development is relatively rapid, and its performance is more stable than DSRC. However, DSRC has a greater advantage in terms of industrial maturity [3]. Based on sophisticated Wi-Fi technology, DSRC technology has been widely used in access control, fleet management, electronic toll collection (ETC) system, and other fields, with more frequent interactions and up to 10 times exact broadcast information per second including vehicle position, speed, and acceleration. With limited mobility and low vehicle density, DSRC can provide end-to-end latency of less than 100 ms and throughput equivalent to 10 kbps [4]. A large number of trials have been carried out globally on 802.11p-based DSRC 2.0 from 2009 to 2021 in preparation for large-scale commercialization [5]. However, due to the openness of the wireless network transmission medium and the mobility of terminals, there are certain security problems and uncertainties in the communication process of the V2X system [6], which may lead to the possibility of eavesdropping, forgery, or replay of information exchanged between vehicles. If the communication system is hijacked and erroneous instructions are issued, it will bring serious security risks to vehicles, personnel, and roads. Therefore, the identification and access control of wireless devices in the V2X systems is particularly important. In view of the current security threats in the V2X systems, the proposed secure communication models and identification technologies include: utilizing the blockchain-based multi-factor authentication models to enhance identification mechanism [7]; using the elliptic curve encryption-based digital signature scheme to strengthen the safe interaction of V2X data information [8]; security authentication between cross-layer and cloud platforms based on cryptographic algorithm technology such as national secret algorithm [9]; utilizing various access security mutual trust authentication protocols simultaneously integrating 5G technology for secure communication of the Internet of Vehicles [10]; using third-party security modules such as cloud servers and certificate servers to authenticate users to protect the confidentiality and integrity of information [11]; etc.