privateness – Can lightning transaction members hyperlink the transaction to on-chain funding transaction UTXOs?
Allow us to begin with the direct fee through channel
Uab. In response to BOLT 02, the fee is carried out by including an HTLC and settling it. From a protocol perspective, Bob doesn’t know if the fee was originated by Alice. After all, as there was initially an bill issued by Bob (and probably introduced out-of-band to Alice), he might deduce that Alice was the payer, however Alice might need forwarded the bill to another person who later routed via Alice. Thus, Bob can not inform with certainty who paid him. All he is aware of is that he obtained cash from Alice.
In that particular setting, Alice can nonetheless make certain that Bob is the one receiving the cash as Bob issued the bill. Invoices are signed by the non-public key similar to the node id, so Alice is aware of that Bob has requested the fee. After all, Bob might need been a proxy within the sense that he issued an bill with the identical fee hash as another person. In that case, Bob might need routed the fee earlier than he was capable of current the preimage. Such conduct can be inconceivable to differentiate for Alice.
Equally, within the Alice-Isidore-Bob setting: Isidore solely is aware of that Alice despatched him cash and that he was requested to ahead to Bob. Isidore doesn’t know if Alice is the originator nor if Bob is the ultimate vacation spot (this after all assumes the protocol is safe and no assaults exist that reveal such info). Like earlier than, Bob solely is aware of that the fee got here via the channel
Uib, however can not inform with certainty who paid him.
Within the Alice-Isidore-Bob setting, Alice is conscious of all funding transactions as she selected the route and the route is encoded with
short_channel_ids which level to funding transactions. Alice will almost definitely have learnt about them through the gossip protocol.