Blockchain-Based Firmware Security Check and Recovery for Smart Inverters

An Overview of Cyber-Resilient Smart Inverters Based on Practical Attack Models

“…CF-IP proactively detects and prevents malicious controllerfirmware update, consequently compromising the control algorithm codes, control setting parameters, and controller input data. An example is a blockchain-based firmware patching for a smart inverter [38] with continuous authentication, integrity, and authorization process during the firmware update and the results are stored in the ledger as security logs. Another example is a controller digital twin method, which exams a new version of controller firmware in a twin controller, while the current version of controller firmware still runs in the main controller [39].…”

“…Once the operating controller-firmware malfunction event is detected, the standby digital twin controller automatically takes over the primary work of the inverter controller. Another example is an automatic firmware rollback and patching process through the blockchain-enabled security module [38]. FF methods should be developed, including controller memory forensics.…”

“…The authors in [35] and [36] introduced cybersecurity vulnerabilities of smart inverters and their impacts on power system operation. Real-time firmware security of smart inverters against controller-firmware modification has been studied [37], [38], [39]. In [39], a power-router prototype using a dual-controller design was proposed to improve uptime and controller-firmware security.…”

A Review of Cyber–Physical Security for Photovoltaic Systems

“…Attackers also exploit software/firmware update events to create cyber-attacks [50], which can directly or indirectly target the inverter controller, as described in Section II.B. The attack surface of software/firmware in a solar farm control center and smart inverters includes three major attack points [51]: 1) Remote vendor access via the regular software update and maintenance; 2) Operator access via a remote user interface; and 3) Physical access via USB flash drives or LAN or reverse engineering/side-channel attacks. Advanced attackers such as advanced persistent threat (APT) groups [52] and insider threats (e.g., disgruntled employees or malicious insiders [53]) can disguise as vendors or authorized users to modify software or Fig.…”

“…Attackers who can access the inverter 'firmware enable' function can modify the behavior of the inverter and lead to malfunction or performance degradation (i.e., stealthy attacks that avoid being detected by intrusion detection systems (IDSs)). For example, the sensor matrix, Y(t), which is generated by embedded sensors in the inverter, can be altered by injecting malicious code in the inverter firmware through flash memory data modification in an inverter control card [55] or over-the-air update [51]. The software/firmware and in-transit data modifications will occur once the chains of cyber-attacks are successful.…”