Validator:
Validators play a critical role in maintaining the integrity and security of a blockchain network. They are responsible for validating transactions and blocks, and ensuring that the network operates according to the rules and consensus protocols set forth by the blockchain.
In a proof-of-work (PoW) blockchain, miners perform the role of validators. They compete to solve complex mathematical problems in order to add new blocks to the blockchain, and are rewarded with cryptocurrency for their efforts. This process ensures that the network is secured by a large number of independent actors, and that transactions are validated in a decentralized and trustless manner.
However, in a proof-of-stake (PoS) blockchain, validators perform the role of miners. Instead of competing to solve mathematical problems, validators are selected to add new blocks to the blockchain based on the amount of cryptocurrency they hold as a stake in the network. This process is known as staking, and it incentivizes validators to act in the best interest of the network, since they stand to lose their stake if they act maliciously or violate the consensus rules.
Validators in PoS blockchains typically need to meet certain requirements in order to participate in the network. For example, they may need to hold a minimum amount of cryptocurrency, run specialized software, and maintain a high level of uptime and reliability. Validators also need to be able to communicate with other nodes on the network in order to receive and validate new transactions and blocks.
One of the key benefits of PoS blockchains is that they consume much less energy than PoW blockchains, since validators do not need to solve complex mathematical problems in order to add new blocks. This makes PoS blockchains more environmentally friendly and sustainable in the long run.
However, PoS blockchains also have their own set of challenges and risks. For example, if a large proportion of the network's cryptocurrency is held by a small number of validators, this can lead to centralization and the potential for collusion or manipulation. Validators also need to be able to secure their own cryptocurrency holdings, since they are at risk of being slashed or losing their stake if they are found to be acting maliciously or violating the consensus rules.
Here are some examples of validators in different PoS blockchains:
Ethereum 2.0:
Validators in Ethereum 2.0 are responsible for creating new blocks and validating transactions on the network. They must stake a minimum of 32 ETH in order to become a validator.
Cardano:
In Cardano's PoS system, validators are called stake pool operators. They are responsible for creating new blocks and validating transactions on the network. To become a stake pool operator, one must stake a minimum of 2 million ADA.
Cosmos:
In Cosmos, validators are responsible for validating transactions and blocks on the network. They must stake a minimum of 10,000 ATOM in order to become a validator.
Tezos:
In Tezos, validators are called bakers. They are responsible for creating new blocks and validating transactions on the network. To become a baker, one must stake a minimum of 8,000 XTZ.