Blockchain technology is all about decentralizing financial systems without a central authority. However, have you ever thought of who runs it? Who ensures the authenticity of crypto transactions? Decentralizing the network means that there are several distributed players who maintain the digital ledger. These players are blockchain nodes.
Nodes are an integral part of keeping the blockchain network functioning and thus, they are the foundation of the very network. Without nodes, the blockchain would not exist in the first place. So, what are these nodes? And what is their role in upkeeping the blockchain? This article will be your ultimate guide on blockchain nodes.
What Are Blockchain Nodes?
The word node is not limited to blockchains. A node refers to a point of intersection within a data communication network. In blockchains, nodes refer to the devices that are linked through a peer-to-peer network. These devices can range from computers, servers, laptops, wallets, and mobile phones. They have the authorization to keep track of the decentralized ledger and act as its communication endpoints.
That means that if you want to interact with all blockchain-based activities you have to do that through nodes. These nodes are constantly updating each other on the current version of the blockchain. For example, when a new block gets added to the blockchain, nodes broadcast to each other the new version of the ledger with the added block.
Since the blockchain operates on a peer-to-peer network, you can consider nodes being peers within the blockchain. Each peer contributes to the network by either validating transactions, creating new blocks, or keeping the historical record of the blockchain. It is important to note that not all nodes have the same responsibilities and tasks (more on that later on).
So, What Is the Objective of Nodes?
Nodes have several objectives depending on the role they are playing. For example, some nodes process crypto transactions by accepting them as valid or rejecting them as invalid. Some nodes have to constantly update the recent copy of the ledger and share it with other nodes to maintain synchronization. So, in short, nodes can:
- Determine the legitimacy of transactions.
- Download and save the recent version of the blockchain.
- Broadcast the latest copy of the ledger to other nodes through communication in order for them to synchronize with the blockchain.
- Provide access to the data that has been stored on the blockchain.
Is a Node the Same as a Miner?
Okay, so if nodes can create new blocks of transactions, that means they are technically miners? Well, not exactly. There are different types of nodes as mentioned earlier. That being said, all miners are nodes, yet not all nodes are miners. Let me explain.
Nodes are devices connected to the peer-to-peer network that operates the blockchain. Nodes require only specific software to connect to the network. That means no fancy mining hardware is needed in order to become a node. Nodes can be full nodes or light nodes.
On the other hand, miners have to operate a full node in order to participate in the consensus process of adding blocks to the blockchain. Unlike nodes, miners have financial incentives to participate in the verification process of transactions. However, running a node doesn’t generate any income. Miners also require specialized hardware and high computing power to validate transactions, which can be energy intensive.
Why Have Thousands of Nodes?
We know now what’s the purpose of nodes in the blockchain network, however, why have a network of nodes instead of one node? This comes to the very reason why blockchains were created in the first place.
In reality, one node can manage and maintain the entirety of the blockchain network. However, blockchains are decentralized ledgers. Meaning that there shouldn’t be one central entity operating the network. Why? This would expose the network to hacks and attacks. In a single-node network, or a few-node network for that matter, attackers can easily find weak points to infiltrate.
However, in a network operated by thousands of nodes, data is dispersed which creates no single point of failure. This creates rigid network security where data written on the blockchain is unhackable and immutable. The more nodes participate in maintaining the blockchain, the more the network is secure.
Types of Blockchain Nodes
Blockchain nodes have different roles to play within a network, and thus, there are several types of nodes within the blockchains.
The first and most important blockchain nodes are full nodes. Full nodes maintain all transaction data in the blockchain. You can consider them as the blockchain’s servers. They verify, authenticate, and store blocks that get added to the blockchain. These nodes store the full history of the ledger and are responsible for the blockchain’s legitimacy.
In addition, full nodes have governance power. This means that any upgrade or improvement to the blockchain network has to be accepted by more than half of the full nodes. However, it’s important to note that even though more than half of the nodes agree on a certain upgrade, it doesn’t necessarily mean that they are the majority. For example, if only 52% of the full nodes agree to a certain upgrade, the blockchain will go into a hard fork and splits into two chains.
Light nodes, or SPV nodes (Simplified Payment Verification), are a lighter version of full nodes. They can be operated on a device with a small storage capacity such as mobile phones or tablets. Unlike full nodes, light nodes don’t store the entire ledger history. Instead, light nodes store block headers relating to a specific block that is being verified.
Light nodes connect to full nodes (generally referred to as their parent nodes) and verify transactions that are stored in a specific block. The advantages of light nodes are that they add to the security of the blockchain by connecting to full nodes, as well as not requiring huge resources to maintain the network.
As said before, mining nodes are a type of full node that takes the responsibility of adding blocks to the blockchain. In proof-of-work blockchains such as Bitcoin, miners have to run a full node in order to participate in the verification process of transactions. Miners verify transactions and group them into blocks. Then, miners have to compete in solving a mathematical puzzle to get the chance of adding a block to the blockchain.
It’s important to note that miners create blocks and add them to the blockchain, however, they do not have the responsibility of maintaining the validity of the entire blockchain.
How Do Nodes Work?
So, how do these different types of nodes maintain the blockchain together? Well, it goes like this:
- A user conducts a transaction on the blockchain.
- The transaction gets broadcasted to all nodes in a blockchain.
- Miner nodes (which are also full nodes) verify the authenticity of the transaction and group it into a block and add it to the blockchain.
- Light nodes request the block from the full node to verify it themselves.
- When miner nodes add the block to the blockchain, full nodes update their copy of the full ledger in order to maintain synchronization.
Running a Blockchain Node
Running a node can be beneficial. For example, it increases the network’s security by reinforcing more decentralization. The more nodes participate in a network, the harder it gets to infiltrate it. It can also give you control over the verification of your own transactions. In addition, running a full node can give you the chance to become a blockchain miner.
How to Set Up a Node
Setting up a node needs a couple of things. First, you have to have the right requirement to set up a node:
- Hardware: First, you have to have a computer with enough processing power and storage to handle storing the blockchain.
- Internet Connection: You have to have a stable internet connection to always be up to date with the latest blockchain version.
- Software: Each blockchain has specific software that gives you the ability to run a node.
- Technical Knowledge: You have to know at least the basic technical knowledge of how the blockchain works.
After having the right requirement, you can choose a blockchain network and sync your node with the rest of the network. It’s important to note that running a node comes with risks. For example, it can expose you to possible hacks and attacks. In addition, it will require significant hardware resources which can be expensive.
The Importance of Blockchain Nodes
While nodes contribute to the security of the decentralized network, their individual security relies on various factors such as consensus mechanism, decentralization, and proper implementation of security measures. For instance, nodes could be subjected to attacks such as DDoS, Sybil attacks, and chain reorganization attacks. This is why it is best for all node operators to keep their identities anonymous.
Nonetheless, nodes are important since they validate transactions, maintain network security, store and distribute data, participate in consensus, synchronize the network, and enable user interactions. They ensure the integrity and functionality of the blockchain network.
As blockchains gain more widespread adoption, more nodes will be joining the network which will increase the overall security of the ledger. Here are the most common blockchain attacks to look out for when running a node.