lightning-dev
Hold fees: 402 Payment Required for Lightning itself
Posted on: October 13, 2020 11:57 UTC
The proposal is to give financial value to the sats and the htlc slot being locked for an amount of time, where the initiator of a multi-hop payment should prepay for all the risk of all the hops.
If not enforced, a small amount relative to the risk that all the hops are taking could be paid by the initiator of a multi-hop payment. When we consider multi-hop payments, then we should consider that the initiator of the multi-hop payment is asking multiple nodes to put their funds at risk. It may be a large enough shift in the incentives of the attacker. The sender needs to trust its peer not to steal the payment and/or artificially delay the forwarding to inflate the hold fee. Trust relation between peers already exists, even in case of high on-chain fee conditions.There are two options available for the prepaid hold fee balance: A) Pay a sum upfront which can be used to cover multiple forwards. B) Tightly integrated with the htlc add/fail/settle messages. In both cases, the sender needs to trust its peer to not steal the payment and/or artificially delay the forwarding to inflate the hold fee. If overcharged continuously on the hold fees, it may outweigh the once-in-a-channel-lifetime chain fees. But if all your payments through a specific node are delayed, it does get suspicious.