Who guarantees I can verify a transaction from last year when full nodes have deleted it?
Opportunity
Ethereum's EIP-4444, activated July 2025, permits execution clients to prune block history older than roughly one year. Blob data from EIP-4844 is pruned even sooner, within 18 days on consensus clients. Applications that depend on historical state proofs, including cross-chain fraud proof windows, compliance audits, and light client bootstrapping, have no trustless source once full nodes stop serving that data. The Portal Network is building a decentralized archive but has not shipped production-ready software. Centralized providers quietly fill the gap, inserting trusted intermediaries into a stack that is marketed as trustless.
Why it matters
If provable chain history can only be retrieved from an operator you have to trust, every protocol that relies on historical state has a silent custodial dependency it cannot audit or replace.
How I score the opportunity
The Opportunity Score is my own read, not a measurement: how much it hurts, how often it bites, and how little exists to solve it today. Higher means I think it is more worth building.
How much pain it causes when it shows up.
How often people actually run into it.
How little good tooling exists for it today.
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