An intermediate node is aware of the earlier hop’s id and the id of the following hop in addition to the forwarded quantity, the hash-lock, and the timeout worth. Typically, a forwarder doesn’t study in regards to the id of sender and receiver.
Forwarding requests are all the time padded to the identical measurement, so a forwarder can’t inform what number of hops preceded or succeed them. Utilizing details about the topology, a forwarder could possibly make educated guesses about origin and vacation spot if they’re the primary or final hops and might assume that their neighbor doesn’t take part in forwarding, e.g. as a result of they do not have (different) public channels or are cellular purchasers which might be solely on-line intermittently. They can’t be sure, as a result of the opposite nodes might have additional personal channels.
Two colluding forwarders can simply establish that they are a part of the identical cost as a result of all of the HTLCs (Hash Time Locked Contracts) alongside the route use the identical hash to arrange the forwarding agreements.
There’s work in progress to interchange HTLCs with Schnorr signature-based Level Time Locked Contracts (PTLCs). In funds utilizing PTLCs every hop has a definite secret which makes it tougher to affiliate forwarding exercise, however even then, quantities, time-out values, and timing of the forwarding requests might suffice to guess that separate hops belong to the identical cost. Combining PTLCs with Multipath Funds would make it even tougher to affiliate completely different hops of funds.