According to official sources, Polyhedra Network has launched a Bitcoin cross-chain message transmission protocol based on zkBridge to improve the interoperability of the Bitcoin network. This innovation aims to enable the Bitcoin network to efficiently and securely interact with other L1 and L2 blockchain networks through cross-chain interoperability.

To promote interoperability between the Bitcoin network and other blockchain networks, it is crucial to achieve a cross-chain protocol where the Bitcoin network serves as both the sending and receiving chain. In the direction where the Bitcoin network serves as the sending chain, the Bitcoin network is fully compatible with Polyhedra Network's zkBridge framework. zkBridge enables the updater contract (i.e., light client contract) on the receiving chain to directly verify the Bitcoin consensus mechanism and verify every transaction on Bitcoin through Merkle proofs. This compatibility ensures that zkBridge can fully cover the PoW consensus proof and every transaction Merkle proof on the Bitcoin network.