# The Role of Blockchain in Improving the Processes and Workflows in Construction Projects
## 2 Blockchain Technology Overview  
Blockchain is a type of database technology that consists of a distributed ledger, a consensus protocol, and cryptography. Blockchain can use a decentralized peer-to-peer network to track and store the past and present status of tangible goods or intangible occurrences. Data are saved in a series of blocks that are linked in a chain. Cryptographic protocols forbid any changes to the data stored in a block without the cooperation or collaboration of the majority of participants [19]. Moreover, it uses a decentralized peer-to-peer network to create a distributed ledger. The users of this network can interact with or transact a variety of information, such as building data, agreements, or ownership records. All interactions on the network are verified by its participants and are then chronologically stored on a certain block on the blockchain. The newly minted block, which contains a certain number of new records, is then propagated to all instances of the ledger across all computers connected to the network. Due to its decentralized nature, blockchain is not prone to manipulation or control by a centralized component because the ledger is duplicated across all computers running it and is used to verify its integrity [20]. Figure 1 illustrates the blockchain operation in terms of sequential steps. To ensure reliability, anyone with access to the blockchain can view the data and track its history on the network [21]. A global advisory firm to the construction industry estimated that only 5% of building construction data are preserved on handover to the first owner [22]. In the construction sector, there is a lack of transparency and trust in working relationships. As a result, there has been a lack of cooperation among project stakeholders, as well as difficulties in exchanging information. This motivates the use of blockchain technology to tackle these issues. Blockchain technology's decentralized feature promotes high transparency and trust and has piqued the interest of numerous industrial sectors, including the construction industry. In a decentralized system, each participant is allowed to access data in an open system with no need for third-party authorization or verification. The validity of the transactions is ensured through consensus and public validation [23]. Furthermore, blockchain technology plays a major role in future worldwide networks leading to a maximization of the movement of information between stakeholders [24]. A consensus mechanism is one of the fundamentals of blockchain used to verify transactions. As a result, all participants must agree for a transaction to be accepted as valid, which means that before any transaction can take place, it must be verified by everyone on the network and encrypted with their private key to ensure that their identity is kept anonymous. Then, a transaction can take place securely and transparently because it is visible to all parties involved in verifying it a few seconds after this validation process has been completed, once again through consensus from all parties involved in the verification [25]. Moreover, immutability is achieved in blockchain technology by making all transactions on the blockchain unchangeable and providing a record for each transaction that cannot be altered. The irreversible blocks generated by the blockchain can be used to settle financial transactions. When cryptographic hashes are chained together to create data files, they cause immutability in the data. Because no one can go back and edit or change any of the existing records, this can be useful for ensuring good quality assurance [26]. Furthermore, smart contract technology could provide a more reliable way to keep track of contracts through a decentralized network. The idea is to create an electronic and self-executing digital agreement between two or more parties. The smart contract could be a process by which construction contracts could be formed and monitored [27].