Blockchain is a concept often perceived as complex and mysterious. This article aims to demystify the constitution of the blockchain, by illuminating the different steps of its creation and its functioning within the network. By understanding how the blockchain is constituted, it will be easier to grasp its importance and potential in various fields, notably finance, data management, and much more.
The blockchain appears as a structured set, a digital ledger of transactions. Each transaction is integrated into a block, and these blocks are linked together in a chain, thereby forming a blockchain. This structure is designed to be secure, transparent, and immutable, so that no transaction can be altered after its recording.
The formation of blocks
Each block of the blockchain is composed of several key elements: the identifier of its predecessor, a list of transactions, a verification code (also called hash), and an indication of the work done for its creation. The identification of the predecessor block is crucial as it ensures the continuity and security of the chain by linking each new block to the one that precedes it.
The process of creating a block begins when a miner proposes a new set of transactions. This block must be validated by the network before it can be added to the blockchain. Validation protocols are in place to ensure that each transaction is legitimate, thus avoiding any possibility of fraud or error.
The role of nodes in validation
Nodes play a fundamental role in the functioning of the blockchain. Each node constitutes a local copy of the transaction ledger. When a node receives a new block, it must verify it to ensure that it complies with established rules. This includes checking the syntax, confirming that the transactions have not already been processed, and the validity of cryptographic signatures.
If the block is valid, it is then added to the node’s blockchain. Otherwise, it is rejected. This process ensures that all copies of the blockchain on each node are identical, thus reinforcing the security and integrity of the system.
The importance of consensus
For the blockchain to function effectively, a principle of consensus is necessary. This means that all nodes must reach an agreement on the state of the chain and the transactions it contains. Different mechanisms, such as proof of work or proof of stake, are used to achieve this objective. A node must choose the version of the chain that required the most work to create, which deters attempts at fraud.
When divergent nodes emit different blocks, a fork may occur. The nodes must then continue to work on their respective versions of the blockchain. However, generally, consensus is restored as soon as a new series of blocks is added and all nodes accept a common version as valid.
Managing orphaned transactions
In some cases, blocks may not be added to the main chain, thus becoming orphaned blocks. This occurs when the predecessor of the proposed block does not yet exist in the version of the blockchain of the node. To manage these situations, the node will attempt to retrieve the missing block from its neighbors.
Managing orphaned blocks is an essential part of the process, as it helps to maintain a consistent version of the blockchain while integrating new information as it is validated.
The inherent security of blockchain
The blockchain is often praised for its security. Each block is protected by a unique hash that prevents any unauthorized modification. If a block were altered, its hash would change, immediately making it evident that tampering had been attempted. Moreover, the validation process by the nodes makes it nearly impossible to introduce fraudulent transactions into the ledger.
For a fraudster to succeed in manipulating the blockchain, they would need to control a significant portion of the network’s computing power, which is extremely difficult to achieve due to the decentralized distribution and the collaborative nature of blockchain operations.
To deepen your understanding, interesting articles on the application of blockchain in public finance management and its challenges can be consulted at the following links: Public Finance Management, Financial Results of Blockchain, Glossary of Blockchain Terms, and many more. You can also discover recent advancements in blockchain by checking this article on the blockchain revolution or the approval of documents on blockchain by the CEPD here.
