Cross-chain

Cross-chain refers to the infrastructure that moves assets or messages between blockchains that can't natively talk to each other. Every chain is an island by default — Ethereum doesn't know Solana's state — so bridges exist to connect them. The basic pattern: lock asset X on chain A, mint a wrapped version on chain B. The hard part is everything else: who verifies the lock happened, who can mint on the other side, what happens if the bridge operator is compromised. Bridges are the single biggest source of exploits in crypto — Ronin ($625M), Wormhole ($325M), Nomad ($190M) — because they hold huge pools of locked capital and their security model is usually weaker than the chains they connect. Safer modern designs (CCIP, LayerZero, native rollup bridges) use cryptographic proofs or decentralised validator sets instead of multisigs.