Smart Grid is an indispensable part of the Internet of Things (IoT) and has the potential to revolutionise the electricity energy industry. Smart meters, as an important component of Smart Grid, are responsible for the exchange of information between end consumers and service providers. Smart meters and service providers need to use authentication key exchange protocols (AKE) to establish a secure session for secure information transmission. However, The current state-of-the-art lightweight solutions do not support identity anonymity and mostly have high communication costs. This paper proposes a lightweight and secure mutual authentication scheme, which is particularly designed for devices with limited computing capability to provide identity anonymity such as smart meters, based on the Shangyong Mima 2 (SM2) AKE protocol stipulated by the State Cryptography Administration of China. We conducted formal analysis of the security of the proposed scheme and proved its security. In addition, the computational overhead of the protocol was evaluated through performance analysis. Compared with related lightweight protocols, our scheme can reduce up to 30%-40% computational overhead. The results verified that the proposed scheme is indeed suitable for secure communication involving devices with constrained computing capability.

The authenticated key exchange (AKE) protocol can ensure secure communication between a client and a server in the electricity transaction of the Energy Internet of things (EIoT). Park proposed a two-factor authentication protocol 2PAKEP, whose computational burden of authentication is evenly shared by both sides. However, the computing capability of the client device is weaker than that of the server. Therefore, based on 2PAKEP, we propose an authentication protocol that transfers computational tasks from the client to the server. The client has fewer computing tasks in this protocol than the server, and the overall latency will be greatly reduced. Furthermore, the security of the proposed protocol is analyzed by using the ROR model and GNY logic. We verify the low-latency advantage of the proposed protocol through various comparative experiments and use it for EIoT electricity transaction systems in a Metaverse scenario.

Wireless Body Area Networks (WBANs) have been deployed in numerous applications, where the most common communication technology is Bluetooth. Bluetooth uses the Numeric Comparison Protocol (NCP) to negotiate session keys based on the Elliptic Curve Cryptography (ECC) and Out-of-Band (OoB) channels. However, the scalar multiplication of ECC is a heavy computing operation for devices in WBANs. To address this issue, we propose the Lightweight and Secure Numeric Comparison Protocol (LSNCP) which requires less scalar multiplication than the NCP in Bluetooth. New logic expressions and rules are proposed to verify the security of LSNCP in GNY logic. The proof shows that LSNCP is secure. We conduct a provable security analysis by integrating the commitment scheme and short hash function. The result shows that LSNCP is secure in the modified Bellare-Rogaway model. Finally, we conduct theoretical analysis and experiments to evaluate the performance of LSNCP. The results confirm that LSNCP has less computation cost than NCP and other benchmark protocols. LSNCP has many potential application scenarios like healthcare, Metaverse, and blockchain.

Wearable devices that collect data about human beings are widely used in healthcare applications. Once collected, the health data will be securely transmitted to smartphones in most scenarios. Authenticated Key Exchange (AKE) can protect wireless communications between wearables and smartphones, and a typical solution is the Bluetooth Secure Simple Pairing (SSP) protocol with numeric comparison. However, this protocol requires equivalent computation on both devices, even though their computational capabilities are significantly different. This paper proposes a lightweight numeric comparison protocol for communications in which two parties have unbalanced computational capabilities, e.g., a wearable sensor and a smartphone, named UnBalanced secure Pairing using numeric comparison (UB-Pairing for short). The security of UB-Pairing is analyzed using the modified Bellare–Rogaway model (mBR). The analysis results show that UB-Pairing achieves the security goals. We also carry out a number of experiments to evaluate the performance of UB-Pairing. The results show that UB-Pairing is friendly to wearable devices, and more efficient than standard protocols when the computation capabilities of the two communication parties are highly unbalanced.