## 4 Digitalization of MGs
### Blockchain Technology  
The integration of blockchain technology into MGs is a recent development that holds significant potential for transforming the energy sector. Blockchain technology, on the other hand, is a decentralized system that allows for secure, transparent, and tamper-proof transactions. The combination of these two technologies can enhance the efficiency, security, and transparency of MGs, enabling them to better meet the energy needs of communities. This section explores the use of blockchain technology in MGs, its benefits, challenges, and future prospects. Blockchain technology is a decentralized, distributed ledger system that is designed to record transactions in a secure and transparent manner. The technology allows participants to maintain a shared and immutable record of transactions without the need for a central authority or intermediary [25; 151; 152]. In a blockchain network, transactions are verifiedand recorded by a network of nodes or computers, which work together to maintain the integrity of the ledger. Each block in the chain contains a record of several transactions, along with a cryptographic hash of the previous block in the chain, which creates an unbreakable chain of blocks. This creates a tamper-proof and transparent record of transactions that is available to all participants in the network. Blockchain technology was first introduced as the underlying technology for the cryptocurrency Bitcoin. However, the technology has since been applied to a wide range of applications beyond cryptocurrency, including supply chain management, identity verification, and decentralized finance [25; 151]. The potential of blockchain technology lies in its ability to provide a secure, transparent, and decentralized record of transactions that can be used across a variety of industries and applications. The layers of a blockchain can be divided into three main layers entitled network layer, consensus layer, and application layer. The network layer is the lowest layer in the architecture and is responsible for managing the communication between nodes in the network. This layer includes protocols such as TCP/IP and HTTP, which enable the transmission of data between nodes. The network layer also includes P2P protocols, which enable nodes to connect to each other and share data in a decentralized manner. The consensus layer is responsible for validating transactions and adding them to the blockchain. This layer includes the consensus mechanism, which is a set of rules that determine how transactions are validated and added to the blockchain. There are various types of consensus mechanisms, such as proof of work (PoW), proof of stake (PoS), and delegated proof of stake (DPoS). The application layer is the top layer in the architecture and is responsible for providing a user interface and enabling the development of decentralized applications (dApps). This layer includes smart contracts, which are self-executing contracts that are encoded on the blockchain. Smart contracts enable the automation of various processes, such as payments, asset transfers, and identity verification. The application layer also includes various tools and libraries that developers can use to build and deploy dApps on the blockchain. Each layer of the blockchain architecture has its unique functionalities and components, but they work together to create a secure and transparent record of transactions on the blockchain. The network layer enables the transmission of data between nodes, the consensus layer ensures the integrity of the transactions, and the application layer enables the development of decentralized applications that can interact with the blockchain. The Integration of blockchain technology into MGs can enhance their efficiency, security, and transparency [151; 153; 154; 155]. One application of blockchain in MGs is P2P energy trading. P2P energy trading allows consumers to buy and sell energy directly from each other, without the need for intermediaries such as utilities or retailers.