What is a bitcoin bridge & how does it work?
Could you elaborate on the concept of a Bitcoin bridge and its operational mechanism? I'm particularly interested in understanding how it enables the transfer of value between different blockchain networks. Is it a type of middleware that facilitates cross-chain transactions? Does it involve any form of custody or escrow? Furthermore, what are the security measures implemented to ensure the integrity and safety of these transactions? Additionally, how does it handle the issue of liquidity when bridging assets between networks? Your insight into this topic would be greatly appreciated.