## 5 Working Operation of Blockchain in Smart Grid (SG)
### Speed of Blockchain-Based Transaction Authentication for EV Consumers  
Although the proposed blockchain-based system can manage transactions in the SG, there are some issues regarding its speed of execution. Current blockchain mechanisms, like the Ethereum blockchain, can currently only handle up to fifteen transactions per second. This is due to the heavy processing involved in solving cryptographic puzzles for 'nonce' calculation in a trustworthy decentralized authentication mechanism. This limitation will have to be revisited if implemented in a full-scale SG catering to the needs of EV consumers. [PERSON] et al. (2012) considered the pertinent problem of renewable energy instability in the blockchain-based SG framework. They tested whether the blockchain can scale to implement real-time power modulation commands through smart contracts on the scale of a few seconds to a few minutes, which will be necessitated in view of the highly volatile EV market. Security and Its Underlying Energy Consumption Issues in Blockchain-Based SG Applications for the EV Market  
Public blockchains pose a challenge in maintaining the privacy of energy market participants, including EV owners, as all transactions and account balances are publicly visible. For instance, a publicly accessible web resource listing Ethereum account information and their balance (Etherescan) (Etherescan) (Etherescan) can compromise the privacy of these EV market players and end-users. To address this, a government-based organization could maintain a mapping between account addresses and owners' identities. However, this approach raises the risk of malicious actors targeting wealthy accounts and tracking their owners. An alternative solution is to implement a hybrid blockchain architecture, which separates transaction records from owner identities. In a hybrid model, participation remains open, but block validation and hosting are restricted to a set of trusted nodes, enhancing the network's security ([PERSON] et al., 2017). Another security concern is that the resource-intensive PoW consensus mechanism contrasts with the carbon footprint reduction potential of EVs. In a public blockchain, individuals with high-performance computing equipment could potentially dominate the system. A potential research direction is to explore consensus mechanisms that consider a node's overall system contribution when selecting eligible block validators, such as the proof-of-importance approach. Two important terms in cyber-attacks on SGs are jamming attacks and false data attacks. Jamming attacks involve occupying the channel and interfering with the broadcast communication reception, while false data attacks impact the control center's computations. It was reported that a large-scale cyber-attack on the London energy network could cost up to GBP 111 million every day ([PERSON] et al., 2017). Cyber-attacks have been carried out regularly on energy or power network providers, with at least one cyber-attack affecting 75% of energy firms in the past year. AI models can be utilized to identify these cyber threats by examining erroneous data and enabling preemptive measures before they affect energy systems. Between accounts and fraudsters, passwords act as a barrier, while AI technology offers biometric authentication for secure and dependable energy operations. Various schemes have been proposed to develop AI applications to detect cyber-attack threats on the SG, including improving the cyber-physical security of IoTs, transient energy-based screening technology, wide-area monitoring protection, and protecting the industrial control system. Wide-area monitoring entails conveying specific local information to a remote site while also using system-wide data to prevent widespread disruption and lessen the likelihood of potential catastrophic outages ([PERSON] et al., 2017). We believe that future cyber security algorithms for EV applications in SG must consider privacy and computational costs as the foremost concerns while being robust to cyber threats.