Is it possible to, without any extra knowledge, send a transaction back to whoever sent you monero?
In say, bitcoin, I know the address of whoever sent me btc, so I can send something back to them without them providing us their address “explicitly”. Can something similar be done in the monero protocol?
this concept has been discussed before as “return addresses”. it would marginally increase the transaction size and thus the storage requirements, but it’s possible and seems reasonable. it looks like no one pursued it since knaccc formalized it. nevertheless it’s on the roadmap (“Future” tab).
https://old.reddit.com/r/Monero/comments/b0gjud/monero_return_addresses_who_would_use_this_feature/
Looks very interesting.
Blockchain bloat indeed is an issue here…
“bloat” would be an exaggeration. if you take 1 in / 2 out transactions as representative, it’s a ~2% increase in transaction size (presuming knaccc’s numbers apply to the presently used Bulletproofs+ transaction format).
If it’s really only a 2% increase it seems worth it imo…
I feel like this would defeat the anonymous factor of monero, but am eager to see if there’s a particular wallet or other tool that could achieve something similiar.
Don’t see how it would, if party A can send funds anonymously to party B, then why can’t party B send funds anonymously to party A. A simple implementation would be to just put a new “(return) address” with each transaction.
Indeed would introduce blockchain bloat. I do feel that this might be an important feature though. Say I need to pay before I can fill up my car, no one knows exactly how much gas I will be buying. I"d like to pay 1XMR and have the unused remainder sent back to me. Sure, not fully trustless but fine for small transactions.
That would be cool to have. Some kind of zero knowledge way of refunding transactions.
correct me if i’m wrong but seraphis update will allow to send back a tx to the sender without revealing the address
