They do and have done for years now. There’s been a files app since 2017. They’ve had Advanced Data Protection available for iOS backups since 2022. Signal has just been lazy and found maintaining the Android backups to be a pain, so they refused to implement it for iOS.

ADP is off by default (this is why iMessage isn’t really e2ee), and importantly, isn’t available in all countries.

I believe in the UK you are legally barred from having access to iCloud ADP.

> I believe in the UK you are legally barred from having access to iCloud ADP.

Apple are still busy fighting the UK government on it in closed-court.

Apple-bashers can continue their hate, but give Apple their due:

    1. they are going in all guns blazing fighting the UK government instead of rolling over
    2. if they succeed, I think they well-deserve the credit.

Can Signal on iOS not save in the Files app like any other app that uses documents?

From the point of view of iOS, yes it can (the person you're replying to is wrong, as explained by the other person who replied to them). But no, the Signal iOS app does not currently have that functionality.

They did support it since they released the Files app, as Signal shows. Nothing changed all these years, yet they're now rolling out backups for iOS too, so the technology is already there.