A Lightweight Secure User Authentication and Key Agreement Protocol for Wireless Sensor Networks

Wireless sensor networks (WSNs) have great potential for numerous domains of application because of their ability to sense and understand unattended environments. However, a WSN is subject to various attacks due to the openness of the public wireless channel. Therefore, a secure authentication mechanism is vital to enable secure communication within WSNs, and many studies on authentication techniques have been presented to build robust WSNs. Recently, Lu et al. analyzed the security defects of the previous ones and proposed an anonymous three-factor authenticated key agreement protocol for WSNs. However, we found that their protocol is vulnerable to some security weaknesses, such as the offline password guessing attack, known session-specific temporary information attack, and no session key backward secrecy. We propose a lightweight security-improved three-factor authentication scheme for WSNs to overcome the previously stated weaknesses. In addition, the improved scheme is proven to be secure under the random oracle model, and a formal verification is conducted by ProVerif to reveal that the proposal achieves the required security features. Moreover, the theoretical analysis indicates that the proposal can resist known attacks. A comparison with related works demonstrates that the proposed scheme is superior due to its reasonable performance and additional security features.