What is a Blockchain Validator & How does PoS Work?

Jon Ganor
Jon Ganor


  • Proof-of-Stake (PoS) is a consensus mechanism that achieves consensus and validates transactions without resource-intensive mining.

  • Validators play a crucial role in PoS by validating and verifying transactions, maintaining network integrity, and proposing new blocks.

  • Becoming a validator involves meeting specific requirements and following steps set by different blockchain networks, such as staking a minimum amount of tokens.

  • Validator rewards are incentives earned by validators for their participation and contributions to the consensus process.
  • Rewards are typically distributed proportionately to a validator's stake or the number of tokens they have committed.

Intro to Proof-of-Stake

Proof-of-Stake or PoS is a mechanism used by blockchain networks to achieve consensus and validate transactions without the need for resource-intensive mining. While Proof-of-Work relies on solving complex mathematical puzzles, PoS selects validators based on how many tokens they hold and are willing to "stake." 

Expand your knowledge about: Ethereum Proof of Stake Guide.

What is a Validator?

A validator is a participant responsible for validating and verifying transactions and maintaining the integrity of the network. Validators play a crucial role in achieving consensus and ensuring the security and efficiency of the blockchain.

Validators are selected based on specific criteria defined by the consensus mechanism employed by the blockchain network. In PoS systems, validators are chosen based on the number of tokens they hold and are willing to "stake" as collateral. The more tokens a validator stakes, the higher their chances of being selected to propose and validate new blocks.

Once selected, validators perform tasks such as verifying transactions, checking the validity of blocks, and proposing new blocks for inclusion in the blockchain. They contribute computational power and resources to maintain the network's operations and ensure consensus.

Validators are incentivized to act honestly and follow the predefined rules of the consensus mechanism. In PoS systems, validators risk losing their staked tokens if they engage in malicious activities or validate invalid transactions. This economic punishment serves as a deterrent and encourages validators to act in the best interest of the network.

By fulfilling their role effectively, validators contribute to the decentralization, security, and efficiency of the blockchain network. Their participation is essential for maintaining a trustless and transparent system that can be relied upon for secure transactions and the execution of smart contracts.

How to Become a Validator? 

Becoming a validator in different blockchain networks, such as Ethereum, Avalanche, and Cardano, involves meeting specific requirements and following certain steps. In Ethereum, validators are required to hold a minimum of 32 ETH as collateral and stake their tokens through a validator client software. For Avalanche, validators, known as "stakers," must hold a minimum of 2000 AVAX and set up a validator node to participate in block validation. In the case of Cardano, validators need to delegate their tokens to a stake pool or run their own stake pool.

It's important to note that these requirements can vary across different blockchains, as each network may have its own specific criteria and processes for becoming a validator. Therefore, staying informed about the latest guidelines and recommendations from the respective blockchain networks is crucial for individuals aspiring to become validators. By meeting the requirements and following the necessary steps, individuals can contribute to the security and consensus of the blockchain network while earning rewards for their participation.

What are Validator Rewards?

Validator rewards refer to the incentives earned by validators for their participation and contributions to the consensus process in a blockchain network. Validators play a crucial role in maintaining the security, integrity, and consensus of the network, and they are rewarded for their efforts and commitment.

The specific mechanism and calculation of validator rewards can vary depending on the blockchain network. In most cases, validators are rewarded with native tokens of the network they validate. E.g., Ethereum stakers are rewarded with ETH Staking Rewards.

These rewards are typically distributed proportionately to the validator's stake or the number of tokens they have committed as collateral. Validators who consistently follow the network's rules, validate transactions accurately, and maintain high uptime are more likely to receive higher rewards.

Validator rewards serve as an incentive to attract and retain validators in the network. They not only compensate validators for the resources and effort they contribute but also ensure the economic security and stability of the network. By receiving rewards, validators are incentivized to act honestly and in the network's best interest. Any malicious behavior or negligence may result in penalties, slashing of rewards, or loss of their stake.

Proof of Work vs. Proof of Stake 

Proof of Work and Proof of Stake are two prominent consensus mechanisms in blockchain networks. While both aim to achieve distributed consensus, their approach and underlying principles differ.

Proof of Work is the original consensus mechanism introduced by Bitcoin. In PoW, miners compete to solve complex mathematical puzzles to validate transactions and create new blocks. The first miner to solve the puzzle gets the right to add the next block and is rewarded with newly minted cryptocurrency. PoW relies on computational power and energy consumption, making it secure but resource-intensive. The main advantage of PoW is its resistance to malicious attacks, as it would require an attacker to control most of the network's computational power.

On the other hand, Proof of Stake eliminates the need for resource-intensive mining. In PoS, validators are selected to create new blocks based on the number of tokens they hold and are willing to "stake" as collateral. Validators are chosen deterministically, with their chances proportional to their stake. PoS offers advantages such as reduced energy consumption and increased scalability. However, it introduces new challenges, such as the "nothing at stake" problem and the need for an effective mechanism to prevent malicious validators.

While PoW has been the traditional choice for many blockchain networks, PoS has gained traction due to its energy efficiency and scalability benefits. Several blockchains, such as Ethereum, Avalanche, and Cardano, have transitioned or are planning to transition to PoS. Each consensus mechanism has its own trade-offs and considerations, and the choice between PoW and PoS depends on a blockchain network's specific goals and priorities.

Final Thoughts 

Becoming a validator on networks like Ethereum and other PoS-based blockchains can be a cost-effective alternative to purchasing Bitcoin ASIC miners and potentially more profitable. With PoS, validators must hold and "stake" a certain amount of cryptocurrency as collateral.  This eliminates the need for expensive mining hardware and the associated electricity and maintenance costs.

Compared to Bitcoin ASIC miners, which require significant upfront investment and ongoing operational expenses, becoming a validator typically requires a smaller initial capital outlay. Validators can participate in securing the network and earning rewards by simply holding and staking their cryptocurrency. This lower barrier to entry allows more individuals to participate in the consensus process and potentially benefit from the rewards.