Ethash with Guardian

Proof of Guardian

Since the hash power of testnet is limited, we will leverage a protection mechanism called guardian to ensure that there are enough hash power in the root chain to protect the network. We will provide a guardian public key as part of the consensus, and the guardians will sign their generated root blocks using the private key, such that the difficulty effectively drops to 1/1000 of the original. However, guardians volunteer to protect the testnet, so they won't have any rewards for mining.

The guardian mechanism specifically designs for the root chain, and the mining difficulty for each shard chain is completely determined by the hash power.

Guardian public key for testnet 2.0

"GUARDIAN_PUBLIC_KEY": "ab856abd0983a82972021e454fcf66ed5940ed595b0898bcd75cbe2d0a51a00f5358b566df22395a2a8bf6c022c1d51a2c3defe654e91a8d244947783029694d"

Guardian public key for mainnet

"GUARDIAN_PUBLIC_KEY": "6f9ed23452ffb7902345ca8dc53292480274a22cc4625f783e84dd3a6e7082d3e17901c7dc1ba3286fbd1fbd295c17c0722c89e7693220e00587b0d96dd64647"