Proof of Quorum means to generate a receipt showing that a majority of the consensus group has voted for the transaction. Each node in the consensus group signs the transaction hash and gossips it to other nodes in the consensus group. Nodes collect these votes, and when the number of votes is more than 50%, these votes form a receipt that can prove consensus on the transaction. Note Shardeum will use both PoQ and PoS (Proof of Stake) consensus algorithms to keep the network safe, where validating nodes can be expected to stake a minimum amount of network coin to ensure they operate as per network protocols while getting slashed for misbehavior.
Further, the consensus algorithm also plays a key role in assigning a ‘node ID’ randomly to validator nodes before they join the network. On Shardeum, there will be a third set of nodes apart from validator and archive nodes, called ‘standby nodes’. These are nodes waiting for their turn to be validator nodes. Standby nodes use-case on Shardeum is not limited to just accommodating more capacity when the demand surges. With the help of node IDs, the network will constantly auto-rotate the validator and standby nodes to make it even more difficult for bad actors to take over at any given point in time.