Can’t addr_i simply be i ? Or their Grin slatepack address? Or the handle they use to talk to one another, e.g. on Telegram ? All these avoid grinding worries.
This is a great idea. At first I didn’t even think about monikers, addresses and etc. I thought about pure natural numbers. There’re actors number 1, 2, 3, and so on. They can be used directly as their x-coordinate (or, better, their hash).
But then I thought numbers can lead to confuses, better use monikers that each actor can pick to itself.
But if monikers or addresses can potentially be dangerous - it’s perfectly fine to stick with natural numbers.
I fail to see how that is possible.
This can happen (theoretically) if the actor state is outdated. Such as: actors already created a transaction that created a coin with this number, but this transaction temporarily disappeared from the blockchain (due to reorgs), or didn’t appear yet, but will in the future.
There’s even more straightforward scenario. There was a transaction built by a quorum you weren’t part of. Hence you don’t know that coin number was already used.
Anyway, this way or another, it’s a very “unhealthy” situation where several owned coins exist which differ only by their value, but not the blinding factor. It’s very easy to prevent (by including coin value in blinding factor generation). Then why not do this?