# A Secure and Scalable Authentication and Communication Protocol for Smart Grids
## 2 Background
### Related Work  
The interconnected networks in smart grid technologies continue to be significantly susceptible to a range of sophisticated cyberattacks, including DoS, replay Attacks (RA), time delay attacks (TDA), false data injection attacks (FDIA), malware attacks, and even social engineering. The ramifications of these threats can encompass economic losses, data breaches, and interruptions to essential services. Figure 1: Overview of smart grid’s secure communication between nodes. Throughout the years, numerous high-profile incidents have underscored the catastrophic potential of cyberattacks on smart grids. In 2007, the Aurora attack [29], conducted by the Idaho National Laboratory, illustrated how malicious software could manipulate grid control systems, culminating in the severe failure of a power generator. In 2010, the infamous Stuxnet worm attack [30] compromised Iranian programmable logic controllers (PLCs) through a USB flash drive, exploiting vulnerabilities to alter SCADA commands and inflicting considerable damage on the nuclear program. The Dragonfly 2.0 [31] campaign in 2014 specifically targeted energy companies, employing spear-phishing techniques and malware-infected websites to gain unauthorized access to critical systems. Between 2015 and 2016, the cyberattack on the Ukrainian power grid [32] successfully leveraged spear-phishing tactics to infiltrate SCADA systems, resulting in extensive substation outages. More recently, in 2019, a DoS attack briefly disrupted the U.S. power grid, and in 2022, the Sandworm group utilized the NikoWiper malware strain to assault Ukraine's energy sector. In 2023, a DoS attack targeted Hydro-Quebec [33], rendering the company's website and customer portal inaccessible. These incidents emphasize the urgent necessity for security standards that incorporate advanced authentication, encryption, and real-time monitoring to protect critical infrastructure. The integration of cryptographic protocols within smart grids is imperative in addressing the escalating risks associated with sophisticated cyberattacks, such as DoS, RA, and FDIA. End-to-end encryption, alongside advanced authentication mechanisms, ensures secure communication and prevents unauthorized access across the vast and interconnected network of the smart grid. Symmetric encryption, renowned for its efficiency, and asymmetric encryption methods, including Rivest-Shamir-Adleman (RSA) [34], elliptic curve cryptography (ECC) [13], and Diffie-Hellman (DH) [35]-based handshakes, are frequently employed in hybrid strategies to optimize security, scalability, and performance. Furthermore, robust authentication protocols enhance security by validating devices and users prior to granting access, while advanced key management frameworks such as advanced key management architecture (ASKMA) and scalable method of cryptographic key (SMOCK), in addition to certificate-based and certifiateless encryption methods, offer effective solutions for maintaining high levels of security. Authentication and key agreement (AKA) protocols aim to balance security and efficiency, ensuring the confidentiality of communication messages while minimizing computational, storage, and communication overheads--an essential requirement for practical deployment, particularly in resource-constrained devices. Since the introduction of an AKA protocol for smart grids by [PERSON] et al. in 2011 [36], researchers have proposed various protocols to address challenges like resistance to ephemeral secret leakage (ESL) attacks, forward secrecy, and user anonymity. ECC-based AKA protocols are increasingly favored due to their smaller key sizes and equivalent security levels to other asymmetric cryptography techniques. However, many existing protocols, as shown in Table 1, such as those by [PERSON] et al. [37] and [PERSON] et al. [38], have been found lacking in areas like users' anonymity and untraceability. Recent advancements include efforts to design protocols robust against emerging threats while maintaining operational efficiency.