What Are Crypto Bridges? How They Work and Why They Get Hacked

Crypto bridges move tokens and data between blockchains that cannot talk to each other on their own. They are also one of the most attacked parts of crypto. This article explains how bridges work and what the numbers show about hacks. Cumulative losses from bridge exploits have passed $4.3 billion since 2021, according to a 2026 guide to blockchain bridges. Bridges also accounted for two of the three largest DeFi exploits in the first quarter of 2026. Each section below covers one part of the story. What Is a Crypto Bridge?