What is the role of a validator in a proof-of-stake network?

@lucienne 

In a proof-of-stake (PoS) network, the role of a validator is to validate and add new blocks to the blockchain. Validators are chosen to propose and validate new blocks based on the stake they hold in the network. They are responsible for maintaining the security and integrity of the blockchain.

Here's an overview of the role of a validator in a PoS network:

1. Block Proposal: Validators take turns in proposing new blocks to be added to the blockchain. The chances of being selected as a block proposer are proportional to the validator's stake in the network. Validators create a block by bundling together a set of transactions and including a reference to the previous block.
2. Validation: Once a block is proposed, it needs to be validated for its correctness and adherence to the network's rules. Validators verify the transactions within the block, check the cryptographic proofs, and ensure the block is valid according to the consensus rules.
3. Block Verification: Validators validate the proposed block by cross-referencing it with their local copy of the blockchain. They ensure that the block fits seamlessly into the existing chain and does not violate any of the network's rules. Validators also validate the signatures and proofs included in the block.
4. Consensus Participation: Validators actively participate in the consensus protocol to agree on the validity of blocks proposed by themselves or other validators. They communicate with each other to reach a consensus on the next block to be added to the blockchain. This may involve voting or other mechanisms depending on the specific PoS protocol.
5. Block Finalization: Once consensus is reached on the validity of a block, it is added to the blockchain and considered finalized. Validators update their local copy of the blockchain to include the new block and repeat the process for subsequent block proposals.
6. Incentives and Penalties: Validators may receive rewards for their active participation in the network and for successfully adding valid blocks to the blockchain. Conversely, validators can also face penalties or loss of stake for trying to add invalid or malicious blocks to the chain.

Overall, validators play a crucial role in maintaining the decentralization, security, and consensus of a PoS network by proposing, validating, and adding blocks to the blockchain in a fair and secure manner.