The goal of this RFC is to define the consensus algorithm used in Solana. This proposal covers a Proof of Stake (PoS) algorithm that leverages Proof of History (PoH). PoH is a permissionless clock for blockchain that is available before consensus. This PoS approach leverages PoH to make strong assumptions about time among partitions.
Nodes on the network can be "up" or "down". A node indicates it is up either by voting as a validator or by generating a PoH stream as the designated leader. Consensus is reached when a supermajority + 1 of the staked nodes have voted on the state of the network at a particular PoH tick count.
Nodes take turns being leader and generating the PoH that encodes state changes. The network can tolerate loss of connection to any leader by synthesizing what the leader ***would have generated*** had it been connected but not ingesting any state changes. The complexity of forks is thereby limited to a "there/not-there" skip list of branches that may arise on leader rotation periods boundaries.
When the `Slash` vote is processed, validators should lookup `PoH hash` at `PoH count` and compare it with the message. If they do not match, the stake at `stake public key` should be set to `0`.
The goal is to discourage leaders from generating multiple PoH streams. When this occurs, the network adopts ticks for that leader's period. Leaders can be slashed for generating multiple conflicting PoH streams during their period.
1. With my signature I am certifying that I computed `state hash` at `PoH count tick count` and `PoH hash`.
2. I will not vote on a branch that doesn't contain this message for at least `N` counts, or until `PoH tick count` + `N` is reached by the PoH stream (lockout period).