Delegated Proof of Work

As discussed in the previous section, validators are chosen on the basis of a hybrid score, and the hybrid score is calculated based on the contributions from Delegated Proof of Work (DPoW), Delegated Proof of Stake (DPoS) and Non-Custodial BTC staking. This section covers the DPoW side of the equation.

Bitcoin miners generate hash power to secure the Bitcoin network, validate transactions, and earn BTC rewards. To even their rewards out over time, Bitcoin miners often contribute their hash power to mining pools, which use the aggregated hash power to increase the pool’s overall chances of mining a Bitcoin block and receiving BTC in return.

When a Bitcoin miner wants to delegate PoW to the Core network, it adds data to the op_return field in the coinbase transaction specifying which Core validator they want to delegate to and where they want their CORE rewards to go. This is done as a Bitcoin block is being mined, so the miners don’t have to choose between securing the Bitcoin and the Core network.

Relayers are responsible for monitoring the Bitcoin network and transmitting blocks and transaction data to the Core network. Within the Core network, an on-chain embedded BTC light client processes the incoming data from relayers and forwards the delegation information (including hash power and Non custodial staking) to the "Delegation Hub." The Delegation Hub serves as the central component responsible for managing and overseeing delegations within the Core network. During a 1-day round, the Core network calculates the DPoW for each validator by counting the number of blocks the miners delegated to a validator one week prior. For instance, if the round occurs on a Thursday, Core will tabulate the DPoW for each validator by counting blocks from last Thursday.

The architecture for this cross-chain communication is illustrated in the diagram below.