📰 Lightning Labs co-founder Olaoluwa Osuntokun proposed LayerTree: letting thousands or even millions of users share a single Bitcoin UTXO while keeping track of each person’s balance and preserving their right to exit unilaterally. It sounds like bringing an exchange’s “everyone shares one pool of money” model on-chain, but the key difference is that users don’t have to trust only the operator’s database.
💡 LayerTree stores users’ balances in an off-chain Merkle Sum Tree, while the chain holds only the shared UTXO and a commitment to the tree’s root. The sum of the balances in the tree must match the funds in the UTXO, and changing any leaf node changes the root. To exit, a user can submit their leaf node, Merkle proof, and signature without the operator’s approval. Here, O(1) means exiting requires just one transaction; it doesn’t mean the proof size stays constant. The proof still grows as O(log N) with the number of users.
🔥 Everyday transfers try to avoid touching on-chain state. A Channel leaf puts a Lightning channel in a tree leaf, with the operator forwarding payments as HTLCs; a voucher is more like a digital check that can be redeemed on-chain. Once the recipient has a signed voucher, they can submit a CLAIM themselves if the operator won’t cooperate, allowing the script to deduct funds from the payer’s balance and create a new leaf.
🤔 But “redeemable on-chain” doesn’t mean risk-free. Alice could sign vouchers for two people that each exceed her balance. Both signatures would be genuine, but there wouldn’t be enough money to cover both, so whoever submits first might get paid. Older vouchers could also become invalid when the leaf’s state number is updated, so until a voucher is settled, it still carries the issuer’s credit risk.
📌 The most appealing part of this design is that it keeps everyday payments off-chain while giving users a way to exit on their own. The real challenge is handling unsettled vouchers and competition over balances. Would you be willing to put your funds into this kind of shared UTXO structure?
#比特币 #LayerTree #LightningNetwork #BlockchainScaling