This is being reported by cointelegraph, but they don't link to the actual filing (of course 🫤). Another stacker cited to the cointelegraph article in the ~news territory, but I think detailed law discussion should be in the ~Politics_and_Law territory.
There is an Eleventh Circuit case on the compelled disclosure of encryption keys, however the facts are not directly analogous here: In re Grand Jury Subpoena Duces Tecum Dated March 25, 2011, 670 F.3d 1335 (11 th Cir. 2004).
While some states (Wyoming through statute, and PA in a State Supreme Court decision) have protections in this area, there is no fully settled Federal law here.
Here is a 2019 Texas Law Review article discussing this area in some detail, though it may be out of date.