40 lines
1.7 KiB
Markdown
40 lines
1.7 KiB
Markdown
# Validators
|
|
|
|
Validators are responsible for committing new blocks in the blockchain.
|
|
These validators participate in the consensus protocol by broadcasting
|
|
_votes_ which contain cryptographic signatures signed by each
|
|
validator's private key.
|
|
|
|
Some Proof-of-Stake consensus algorithms aim to create a "completely"
|
|
decentralized system where all stakeholders (even those who are not
|
|
always available online) participate in the committing of blocks.
|
|
Tendermint has a different approach to block creation. Validators are
|
|
expected to be online, and the set of validators is permissioned/curated
|
|
by some external process. Proof-of-stake is not required, but can be
|
|
implemented on top of Tendermint consensus. That is, validators may be
|
|
required to post collateral on-chain, off-chain, or may not be required
|
|
to post any collateral at all.
|
|
|
|
Validators have a cryptographic key-pair and an associated amount of
|
|
"voting power". Voting power need not be the same.
|
|
|
|
## Becoming a Validator
|
|
|
|
There are two ways to become validator.
|
|
|
|
1. They can be pre-established in the [genesis state](./using-tendermint.md#genesis)
|
|
2. The ABCI app responds to the EndBlock message with changes to the
|
|
existing validator set.
|
|
|
|
## Committing a Block
|
|
|
|
_+2/3 is short for "more than 2/3"_
|
|
|
|
A block is committed when +2/3 of the validator set sign [precommit
|
|
votes](../spec/blockchain/blockchain.md#vote) for that block at the same `round`.
|
|
The +2/3 set of precommit votes is called a
|
|
[_commit_](../spec/blockchain/blockchain.md#commit). While any +2/3 set of
|
|
precommits for the same block at the same height&round can serve as
|
|
validation, the canonical commit is included in the next block (see
|
|
[LastCommit](../spec/blockchain/blockchain.md#lastcommit)).
|