Comhroinn Fuaime

The Problem In a blockchain network, a block proposer creates a block containing a block header and block content. Full nodes store and validate everything. Light nodes — the majority of participants — store only block headers due to resource constraints. The fundamental problem is this: a light node accepting a block header has no guarantee that the corresponding block content actually exists on the network. A malicious block proposer could publish a valid-looking header while withholding the c