Standard blockchain ledgers like Ethereum cannot mathematically enforce the future use of an asset without taking control of it first.
Current account-based systems have a structural flaw that makes it impossible to guarantee an asset's future fate while the owner still holds it. This impossibility proof explains why many complex financial contracts on the blockchain are so clunky. The researchers proposed a new cryptographic envelope based on commitments to solve this. This allows for non-custodial enforcement where the rules are set in stone without the user giving up their keys. It opens the door for a new generation of decentralized finance that is both more secure and more flexible.
Write-Domain Separation and Non-Custodial Enforcement: A Structural Impossibility in Account-Based Ledgers, with a Commitment-Based Construction
arXiv · 2605.01210
Account-based ledgers -- standard externally-owned accounts (EOAs), ERC-4337 smart accounts, post-Pectra EIP-7702 delegated EOAs -- place the holder of the controlling key at the apex of asset authorization. We ask a structural question about ledger access control: under this authorization model, can a protocol enforce the future disposition of an asset without taking custody and without requiring the owner's cooperation at enforcement time? We formalize the target as Non-Custodial Enforced Encu