# A Secure and Lightweight Group Mobility Authentication Scheme for 6 LoWPAN Networks
## 1 Introduction  
Introducing the Low-Power Wireless Personal Area Network (6 LoWPAN) has significantly increased the scalability of the Internet of Things (IoT) infrastructure. As a result of its ability to effectively integrate IPv6 over low-power wireless networks, 6 LoWPAN has enabled widespread connectivity and enhanced communication among a variety of IoT devices [1]. With this advancement, sensor networks will be deployed more extensively and diversely, facilitating more incredible innovation and expansion in the IoT sector. It is estimated that 29 billion IoT devices will be deployed by 2030 due to the IoT communication used in various industries, including healthcare, agriculture, manufacturing, and transportation technologies [2]. More than 80 companies are standardizing a protocol on a 6 LoWPAN layer called \"Thread\", which allows smart home devices to be connected andcontrolled optimally [3]. 6 LoWPAN sensor nodes are typically resource-constrained devices with limited processing power, memory, and energy capacity. While 6 LoWPAN nodes can feasibly perform lightweight symmetric cryptographic operations such as Advanced Encryption Standard (AES) and Hash-Based Message Authentication Codes (HMACs), more computationally intensive asymmetric cryptographic operations, like Elliptic Curve Cryptography (ECC), are challenging to implement directly on these devices [4]. To address these limitations, cryptographic tasks can be offloaded to intermediary entities, such as access gateways or authentication servers, ensuring secure communication while preserving the nodes' energy and computational resources. This heterogeneity in resource capabilities necessitates lightweight and efficient security solutions designed specifically for the 6 LoWPAN environment [1]. The 6 LoWPAN-based wireless sensor network (WSN) has dramatically expanded the application space of WSNs, and an increased number of mobile devices are connected to the Internet, so seamless Internet connectivity is increasingly important [5]. IoT ecosystems are rapidly adopting mobile devices, which increases the demand for secure, lightweight, and scalable group authentication protocols [6]. In 6 LoWPAN networks, secure communications for mobile devices are further complicated by frequent handovers, resource constraints, and the need for mobility-specific protection. Mobile IPv6 (MIPv6) was developed to ensure seamless communication for mobile devices by maintaining uninterrupted network connectivity as devices move across domains [7]. Building upon this foundation, the Internet Engineering Task Force (IETF) introduced Proxy PMIPv6, a network-based localized mobility management protocol designed to reduce signaling overhead, particularly for resource-constrained 6 LoWPAN nodes. Despite these challenges, PMIPv6 enables resource-constrained devices to function efficiently by delegating cryptographic tasks to access gateways and reducing mobility-related signaling overhead. PMIPv6 reduces signaling overhead by delegating cryptographic and mobility-related tasks to access gateways, enabling efficient operation of low-power nodes [8]. However, despite its benefits, PMIPv6 still faces challenges in ensuring secure and scalable group authentication, particularly during group handovers, where multiple devices transition across domains simultaneously. Existing solutions often fail to provide robust protection against key leakage, ensure Perfect Forward Secrecy (PFS), or resist various advanced threats. These challenges highlight the need for an advanced, secure, and lightweight authentication scheme that can address the unique requirements of 6 LoWPAN networks while ensuring efficient and secure group mobility.