Quiz — Cross-Chain Bridges
Question
Recap the six lessons: bridge trilemma + five trust models, light clients as gold standard, OP Standard Bridge + CCIP + Wormhole + IBC, and the minimal Rust-relayer + Solidity-verifier bridge.
Principle (minimum model)
- Trust-model recap. Five models (custodial / multi-sig / optimistic / light client / atomic swap). Bridge trilemma forces a trade-off (trust-minimised + cheap + fast → pick two). $2 B+ in hacks since 2021 — trust-anchor compromise dominates.
- Light-client primitive. Tracks consensus (sync committee + BLS verification), verifies Merkle proofs against headers. Helios = Rust reference. Expensive on-chain (~140 K gas) but trust-minimised.
- Production bridge zoo. OP Standard Bridge = optimistic rollup deposit/withdrawal (7-day window). CCIP = 12-node DON for Tempo stablecoin transfers. Wormhole = 19-Guardian federated (2022 $325 M hack). IBC = on-chain light clients between Cosmos chains.
- Minimal bridge build. Three components (Solidity light-client verifier + Rust relayer using Alloy + Solidity bridge contract). Reth SDK can host the verifier as a precompile.
Worked example + steps
Final quiz: cross-chain bridges
The cross-chain final check. You'll need this to architect any bridge that touches Tempo, Hyperliquid, or any Reth-based L1.
Summary (3 lines)
- Seven questions spanning trust models, light clients, production bridges, and the minimal-build pattern.
- Get three or more wrong → re-read the relevant lesson before moving on.
- Pass → cross-chain track complete. Next: sequencer / validator / p2p Advanced tracks, or jump into Building OpenHL for the practical openhl Rust implementation.