As earlier described in this question, I was asked today by my iPad to enter the user account password of my MacBook, and my MacBook later asked me to provide the passcode of my iPad. I'm specifically not talking about my iCloud password, the actual device passwords were requested and this behaviour is kind of known.
Now my question is: What happens to these passwords? Are they sent over to Apple? Are they used locally to decrypt something that has been encryted with that passcode?
So is Apple in possession of data that can be used to run brute-force attacks agains my device passwords? This would be totally against the idea of the T2-chip limiting brute-force attacks and I never agreed that such information is sent over to Apple and at no point was I informed about that. I'm not sharing my KeyChain with iCloud and do not wish to.
I couldn't find any exact information on that matter, anybody shedding some light on it is highly welcomed.