Time locked puzzle for payment in Lightning Network


Currently HTLC's timeout transaction relies on absolute timelock enforced on the script. It allows a counterparty to withdraw the money from the contract if the other party doesn't release the preimage. What would have been the problem if instead of using timelock before the counterparty can unlock its money, the condition is replaced with timelock puzzle? The time taken to solve the puzzle will be same as the locktime of the offchain contract.

Subhra Mazumdar

Posted 2020-08-25T11:21:06.400

Reputation: 183

How do you (gu)estimate the "time taken to solve the puzzle" ? – darosior – 2020-08-25T11:25:49.557

That can be decided by the sender who wants to initiate payment – Subhra Mazumdar – 2020-08-25T11:37:22.660

Lightning HTLCs use relative timelock (CSV) not absolute (CLTV). This is because we don't know when the commitment tx will be confirmed (it is offline) – pinhead – 2020-08-25T11:43:56.237

1I was talking about the timeout period of HTLC within which the counterparty must provide the preimage in order to claim payment. Isn't that using an absolute timelock? – Subhra Mazumdar – 2020-08-25T12:01:21.370

sorry you're right - in fact CSV and CLTV are both employed in different LN use cases: https://github.com/lightningnetwork/lightning-rfc/blob/master/03-transactions.md

– pinhead – 2020-08-25T12:13:20.497

No answers