Light Client Architecture
Light Client Architecture involves designing blockchain nodes that can verify the state of the network without downloading and validating the entire blockchain history. These nodes only store the block headers, which contain the cryptographic hashes of the previous blocks and the state root, allowing them to confirm that a transaction is included in the chain.
This approach is highly efficient, enabling resource-constrained devices like mobile phones or IoT sensors to participate in network verification. In the context of cross-chain bridges, light clients are essential for enabling one chain to verify the state of another in a trust-minimized manner.
By checking block headers, the bridge can confirm the validity of events on the source chain without needing to trust a centralized relayer. This architectural choice significantly reduces the trust requirements of the overall system.