Celestia light nodes 🧵
Why they’re more secure than typical light clients and how they help to scale and secure the network.
Light clients are important in a blockchain network to allow individuals to participate as a non-consensus node without the overhead of full nodes.
Light clients typically only download block headers, and don’t verify transactions themselves. This gives them weak security guarantees compared to full nodes as they rely on an honest majority assumption and assume the chain is valid by default.
Celestia light clients have stronger security guarantees and engage in processes that secure the network. Because Celestia light clients have practically the same security as full nodes and take an active role in securing the network, we call them “light nodes.”
The magic that powers light nodes is called data availability sampling. Data availability sampling is a process where light nodes request a random sample of block data. This allows light nodes to verify that the block data is available without downloading the entire block.
Turning an honest majority assumption for a light client into a minimum number of light nodes assumption, and a one honest full node assumption. This allows Celestia light nodes to contribute to the throughput and security of the network with lower hardware requirements.