How do cross-chain bridges work? A case on Wormhole (Part 1)

It might be a bit surprising to our readers that crypto hacks caused over $3 billion lost of funds in 2022. However, a majority of the lost was on cross-chain bridges (e.g., Ronin Network, Wormhole, Nomad, BNB Token Hub, Horizon, Qubit).

Why are cross-chain bridges so vulnerable? Are they not designed or implemented carefully? On the contrary, due to their high value they are developed with the highest possible standards by some of the best engineers (e.g., leoluk). The real reason is that cross-chain bridges are just too…