VALIDATOR

A blockchain is a type of distributed ledger technology (DLT) that consists of growing list of records, called blocks, that are securely linked together using cryptography. Each block contains a cryptographic hash of the previous block, a timestamp, and transaction data (generally represented as a Merkle tree, where data nodes are represented by leaves). The timestamp proves that the transaction data existed when the block was created. Since each block contains information about the previous block, they effectively form a chain (compare linked list data structure), with each additional block linking to the ones before it. Consequently, blockchain transactions are irreversible in that, once they are recorded, the data in any given block cannot be altered retroactively without altering all subsequent blocks.

Blockchains are typically managed by a peer-to-peer (P2P) computer network for use as a public distributed ledger, where nodes collectively adhere to a consensus algorithm protocol to add and validate new transaction blocks. Although blockchain records are not unalterable, since blockchain forks are possible, blockchains may be considered secure by design and exemplify a distributed computing system with high Byzantine fault tolerance.

Proof-of-stake (PoS) protocols are a class of consensus mechanisms for blockchains that work by selecting validators in proportion to their quantity of holdings in the associated cryptocurrency. This is done to avoid the computational cost of proof-of-work schemes. The first functioning use of PoS for cryptocurrency was Peercoin in 2012.

For a blockchain transaction to be recognized, it must be appended to the blockchain. In the proof of stake blockchain the appending entities are named minters or validators (in the proof of work blockchains this task is carried out by the miners); in most protocols, the validators receive a reward for doing so. For the blockchain to remain secure, it must have a mechanism to prevent a malicious user or group from taking over a majority of validation. PoS accomplishes this by requiring that validators have some quantity of blockchain tokens, requiring potential attackers to acquire a large fraction of the tokens on the blockchain to mount an attack.

Proof of work (PoW), another commonly used consensus mechanism, uses a validation of computational prowess to verify transactions, requiring a potential attacker to acquire a large fraction of the computational power of the validator network. This incentivizes consuming huge quantities of energy. PoS is more energy-efficient.

Early PoS implementations were plagued by a number of new attacks that exploited the unique vulnerabilities of the PoS protocols, eventually two dominant designs emerged: so called Byzantine Fault Tolerance-based and Chain-based approaches.

A blockchain validator is someone who is responsible for verifying transactions on a blockchain. Once transactions are verified, they are added to the distributed ledger. In proof of work (PoW) systems like Bitcoin, validators, also known as miners, solve complex computational math problems in order to win the right to verify transactions and receive rewards for the «work». In proof of stake (PoS) systems validators are given rewards as long as they stake the network’s token and correctly participate in the network. This mechanism helps secure the network by imposing the need to lock up value in the network in order to participate in the consensus decisions.

Even if it is not a Validator, there is a way to participate indirectly in the consensus process. It is to delegate stake to a specific Validator. Every node on the network can delegate stake to a specific Validator. This node is called Delegator.

The voting power of the delegated Validator will be increased by the delegated stake, and the compensation to be received by the Validator will also increase accordingly. At this time, the Delegator that has delegated his own stake will also receive a portion of the compensation that the Validator will receive as compensation for delegation. The stakes that have been deposited to become a Validator are bound to be unavailable while the node is acting as a Validator. If the Validator performs malicious actions such as not following the agreed consensus mechanism, some of or all of the deposits will disappear. This is a kind of punishment concept for the unfair conduct of the consensus process, which solves the Nothing at Stake problem of the traditional PoS algorithm.

A node operator runs software that keeps a full copy of the blockchain and broadcasts transactions across the network. Nodes are needed in order to make blockchains work.

An operator ensures that nodes run with enough resources to keep nodes stable and performant. Nodes need to have enough RAM, disk space, bandwidth, etc. to stay operational and serve the network.