For the specific principle, you can refer to:
https://top.game/help/provably-fair
Well, this time i was wrong, if the result is based on the previous game then you are using a good provably fair engine, i have seen people doing this kind of provably fair for games like crash in the past.
I got confused because i only saw the seed and salt, and for a moment i thought you were taking random salts for each round, casinos like freebitco do it, and i don't feel that's a good provably fair method, but you are implementing a good one, so, good luck with your project and thanks for offering a fair engine to the community, we need more of those.
Thank you.
Our vision is to strive to create a fair gaming environment so that players can enjoy the real joy of the game!