Answer to the question, is there a way to eliminate the last round in the SlateStore

[Anynomouss]

After thinking of a relay solution that I call the transaction Buddy System, I red again your SlateStore proposal. I realized that it is very similar, it basically answers one of the open questions at the end of the SlateStore proposal.

The Buddy System is approximately the same as Slate store but uses consecutive RSR and then SRS transaction with a known PubKey from the receiver in order to eliminate the last round of interaction with the sender. Although it is a neat trick to eliminate the need for the sender to stay online and finalize the transaction, the Buddy System has its own sets of problems, namely the need to use a publicly know PubKey of the receiver. Although thanks to cut-through the output with this known public key never needs to appear on chain, it is still a major disadvantage since the intermediary can brute-force values for v to till he finds one that matches the output commitment for the receiver.. For the full details see this proposal.

https://github.com/Anynomouss/grin-for-muggles/blob/main/transaction_buddy_system.md