[AdrianB1]

Not a lawyer, but I read about cases where the judge put people in prison for contempt because they refused to disclose passwords for encrypted content. There was a guy that was in prison for more than 1 year in such a case.

[NegativeK]

To the extend that I've read, they can demand that they hand over data/documents that they know exist, regardless of whether they're encrypted. It's akin to being forced to open a safe if they have a search warrant for a specific document.

What they can't do is say "decrypt this blob and let us look around".