The proliferation of Internet of Things (IoT) devices across multiple domains has heralded an era of unprecedented connectivity and data exchange. Fog computing enhances edge-network processing, enabling real-time data analysis and prompt responses. However, ensuring secure and trustworthy communication among these devices remains a paramount concern. In fog-enabled IoT environments, securing communication among users, IoT devices, gateways, and fog nodes is of paramount importance to prevent unauthorized access and ensure data integrity and confidentiality. Additionally, users can control and deliver instructions to IoT devices remotely. Hence, we propose a blockchain-assisted authentication protocol tailored specifically for fog-enabled IoT environments to verify the user’s identity prior to accessing the IoT devices. The proposed protocol leverages cutting-edge crypto primitives like elliptic curve cryptography, hash functions, and blockchain to establish secure communication between users and IoT devices. Furthermore, we evaluate the proposed scheme through formal (Scyther) and informal analysis, demonstrating its efficacy in mitigating well-known attacks. On the other hand, the proposed protocol exhibits robustness against relevant protocols in terms of communication and computational aspects, as well as reliability for real-world fog-enabled IoT applications.

Integrating advanced communication technologies has significantly enhanced power distribution efficiency, reliability, and sustainability in the evolving landscape of smart microgrids. However, this integration introduces substantial security challenges, particularly concerning authentication and critical agreement processes, which are essential for maintaining the integrity and confidentiality of smart grid communications. This paper presents a novel authentication and key agreement protocol specifically designed for the smart grid environment by incorporating advanced cryptographic techniques such as ECC, physical unclonable functions, and blockchain. Our protocol ensures mutual authentication between devices, robust key management, and resistance to prevalent security threats. We conduct a comprehensive security analysis and performance evaluation, demonstrating that our protocol enhances security and maintains the efficiency necessary for practical deployment in smart grids. The results indicate significant improvements in security and performance metrics compared to existing solutions, establishing our protocol as a viable and effective option for securing smart grid communications. • Blockchain-based key management ensures scalable, resilient data exchange. • Novel ECC- and PUF-driven protocol enables secure smart microgrid authentication. • Protocol achieves mutual authentication, session secrecy, and forward secrecy. • Resistant to replay, man-in-the-middle, cloning, and physical attacks. • Supports lightweight operations suitable for real-time smart energy systems.

Accessing social networking sites is a widespread application of smartphones. If these sites are not adequately protected, users’ personal information on these platforms can become an attractive target for intruders. Access to these sites is typically protected with the more conventional user authentication methods, such as PIN-based or pattern locks, which are vulnerable to a wide range of threats. These authentication measures are also vulnerable to being bypassed by attackers who seek to gain access to social networking sites in order to steal users’ personal information. BrightPass, a malware-resistant authentication system based on screen brightness, was introduced to circumvent these issues. However, it is possible to deduce the PIN numbers from the user’s previous authentication sessions by examining the recorded input. To mitigate this vulnerability, we propose a solution called BlinkPass that works using PIN-based authentication. This approach does not limit itself to securing social media sites; it can be extended to any application where a PIN-based security mechanism can be deployed.

This comment paper refers to an article published by Leu and Hsieh in IET Information Security in the year 2014. Leu and Hsieh proposed a remote user authentication protocol for distributed systems using smartcard. Their protocol affords user anonymity and no verification tables at either end, which can decrease the storage space along with the computations. Their protocol can resist security attacks and is efficient compared with few relevant protocols in terms of computational cost. However, this comment paper brings questions about the correctness of the design of Leu and Hsieh's protocol.

A two-factor authenticated key-agreement scheme for session initiation protocol emerged as a best remedy to overcome the ascribed limitations of the password-based authentication scheme. Recently, Lu et al. proposed an anonymous two-factor authenticated key-agreement scheme for SIP using elliptic curve cryptography. They claimed that their scheme is secure against attacks and achieves user anonymity. Conversely, this paper's keen analysis points out several severe security weaknesses of the Lu et al.'s scheme. In addition, this paper puts forward an enhanced anonymous two-factor mutual authenticated key-agreement scheme for session initiation protocol using elliptic curve cryptography. The security analysis and performance analysis sections demonstrates that the proposed scheme is more robust and efficient than Lu et al.'s scheme.

In 2012, Mun et al . proposed an enhanced secure authentication with key‐agreement protocol for roaming service in global mobility networks environment based on elliptic curve cryptography. They claimed that their protocol is efficient and resistant to prominent security attacks. The careful analysis of this study proves that Mun et al . 's protocol is susceptible to several attacks such as replay attack, man‐in‐middle attack, user impersonation attack, privileged insider attack, denial‐of‐service attack, no login phase and imperfect mutual authentication phase. In addition, this study proposes an enhanced lightweight authentication with key‐agreement protocol for mobile networks based on elliptic curve cryptography using smart cards. The proposed protocol is lightweight and perfectly suitable for real‐time applications as it accomplishes simple one‐way hash function, message authentication code and exclusive‐OR operation. Furthermore, it achieves all the eminent security properties and is resistant to various possible attacks. The security analysis and comparison section demonstrates that the proposed protocol is robust compared with Mun et al . 's protocol.