# PBS for DAS idea collection ## Builders provide samples Along with their block, builders publish an IP address and port where samples can be requested, Downsides/attacks - Builder can be DOSed - Builder can stop serving samples after short period, so behind/syncing clients think data is not available - Builder can selectively withhold, e.g. to throw a number of stakers off the chain and cause a chain split ## Supernodes The network consists of light nodes and supernodes. The supernodes keep all samples. All nodes need to always be connected to at least one honest supernode to ensure they can get all samples from their peers. If validators are required to run supernodes, this design can ensure that enough supernodes will be available (Celestia design). Downsides/attacks - Supernodes are expensive to run. Without requiring validators to run them, there may be very few (maybe 10s) on the network? - Requiring validators to be supernodes is makes at-home validation impractical ## Sample providers Similar to the supernode idea, but with public facing entities that provide samples to validators. They can either do this as a free service (like Etherscan), maybe after a simple registration process to limit DOS attacks, or as a paid service like Infura. Downsides/attacks - If there are no freely accessible sample providers, setting up a node can be cumbersome as it involves registration and/or setting up payment methods - Each node should subscribe to at least a handful of providers to protect against selective withholding attacks