What is a blockchain validator node?

Alan Sunny

Feb 8, 2023 — 5 min read

A blockchain validator node is a computer that performs the task of validating transactions and adding them to the blockchain. In a blockchain network, validator nodes play a critical role in maintaining the integrity and security of the ledger by verifying the validity of transactions and ensuring that only valid transactions are added to the blockchain.

Validator nodes typically receive transaction data from the network and perform various checks, such as verifying that the transaction is properly formatted and signed, and ensuring that the sender has sufficient funds to make the transaction. Once a transaction has been validated, the validator node will broadcast it to other nodes in the network, who will then also validate the transaction and add it to their own copy of the blockchain.

In some blockchain systems, such as proof-of-stake networks, validator nodes are also responsible for creating new blocks and adding them to the blockchain. To incentivise participation and ensure that the network operates in a decentralised and trustless manner, validator nodes may be rewarded with newly minted coins or transaction fees for their work.

Another interesting article describes how you can upgrade to geth node.

Validator nodes process

The process of a validator node in a blockchain network typically involves the following steps:

Receive transactions: A validator node receives transactions from other nodes in the network or from users who initiate transactions.
Validate transactions: The validator node performs various checks to validate the transaction, such as verifying that the transaction is properly formatted, signed, and that the sender has sufficient funds to make the transaction and validator nodes decide if its a valid transaction.
Add the transaction to a block: Once a transaction has been validated, the validator node will add it to a block of transactions, which will be broadcast to other nodes in the network.
Broadcast the block: The validator node broadcasts the block of transactions to other nodes in the network, allowing them to validate the transactions and add them to their own copy of the blockchain.
Consensus process: The validator node participates in the consensus process to determine which blocks will be added to the blockchain. In a proof-of-stake network, this may involve voting on the validity of blocks and creating new blocks.
Update the blockchain: The validator node updates its copy of the blockchain with the newly added blocks.

It's important to note that specific validator nodes process may vary depending on the type of blockchain network and the consensus mechanism used. For example, in a proof-of-work network, the validator node may perform additional steps, such as solving complex mathematical problems to create new blocks.

How blockchain software works?

Blockchain software enables secure, transparent, and tamper-proof transactions by using a decentralized network of nodes, consensus algorithms, and cryptographic techniques.

How Proof of work blockchain works?

Proof of Work (PoW) is a consensus algorithm used by most cryptocurrencies, including Bitcoin. It is a process by which a node in a blockchain network validates transactions and creates new blocks.

Here's how Proof of Work works in a nutshell:

A node (also called a miner) collects a group of transactions into a block.
The miner then computes a mathematical puzzle, called a hash function, based on the data in the block. The hash function must have a specific format, such as starting with a certain number of zeros.
The miner tries to find a nonce (a random number) that, when combined with the data in the block, creates a hash that meets the required format.
Once the miner finds the nonce, it broadcasts the block, including the nonce, to the network for validation.
The other nodes in the network verify that the hash is correct and that all the transactions in the block are valid. If so, the block is added to the blockchain and the miner is rewarded with some cryptocurrency, such as Bitcoin.
The process then repeats with a new block, and the blockchain continues to grow.

PoW is designed to be a slow and resource-intensive process, making it difficult for a single entity to control more than 50% of the network's computing power (also known as a 51% attack). This helps ensure the security and integrity of the blockchain.

How Proof of stake blockchain works?

Proof of Stake (PoS) is a consensus algorithm used by some cryptocurrencies as an alternative to Proof of Work (PoW). It is designed to be more energy-efficient and secure than PoW.

Here's how Proof of Stake works in a nutshell:

Instead of requiring nodes to perform computationally intensive tasks to validate transactions and create new blocks, PoS relies on nodes holding a stake (or ownership) in the network. This stake is usually represented by a certain number of coins that the node has locked up.
To participate in the validation process, a node is selected at random to validate a block of transactions. The likelihood of a node being selected is proportional to its stake in the network. For example, a node with 10% of the total stake will be selected 10 times more often than a node with 1% of the total stake.
The selected node, also known as a validator, verifies the transactions in the block and adds it to the blockchain. The validator is then rewarded with transaction fees for their work.
If a validator tries to validate a fraudulent block, they stand to lose their stake. This creates an incentive for validators to act honestly and helps ensure the security and integrity of the network.
The process then repeats with a new block, and the blockchain continues to grow.

PoS is designed to be more energy-efficient than PoW, as it does not require nodes to perform intensive computations. It also makes it more difficult for a single entity to control more than 50% of the network's stake, helping to ensure the security and decentralization of the blockchain.

Requirements to Become a blockchain Validators

Technical requirements: Validator nodes must have a reliable and high-performance computer system with sufficient storage, processing power, and network bandwidth to support the demands of validating transactions and participating in the consensus process.

Technical knowledge: Validator nodes must have a good understanding of blockchain technology and be familiar with the specific blockchain network they want to participate in, including its consensus mechanism, cryptography, and data structures.

Staking: In proof-of-stake blockchain networks, validator nodes are required to hold a certain amount of the network's native cryptocurrency as collateral, known as "staking." This requirement is designed to incentivize validators to act in the best interest of the network and to ensure their reliability and availability.

Lets look at the validator requirement for some of the largest blockchains.

Bitcoin validator nodes requirement

Desktop or laptop hardware running recent versions of Windows, Mac OS X, or Linux.
7 gigabytes of free disk space, accessible at a minimum read/write speed of 100 MB/s.
2 gigabytes of memory (RAM)
A broadband Internet connection with upload speeds of at least 400 kilobits (50 kilobytes) per second
An unmetered connection, a connection with high upload limits, or a connection you regularly monitor to ensure it doesn’t exceed its upload limits. It’s common for full nodes on high-speed connections to use 200 gigabytes upload or more a month. Download usage is around 20 gigabytes a month, plus around an additional 340 gigabytes the first time you start your node.
6 hours a day that your full node can be left running. (You can do other things with your computer while running a full node.) More hours would be better, and best of all would be if you can run your node continuously.

Ethereum validator nodes requirement

To run an ETH 2.0 node one needs:

Validator client — Responsible for producing new blocks and attestations in the beacon chain and shard chains.
Beacon chain client — Responsible for managing the state of the beacon chain, validator shuffling, and more.
Eth1 node — Supplies incoming validator deposits from the eth1 chain to the beacon chain client.

In this case, our Eth1 node will be connected to the Goerli network. Moreover, in this tutorial, the validator client, beacon chain client, and Eth1 node will all be set up on the same machine.

Machine Requirements: