I don't know why you're being downvoted. For a start, if it was a third party that had the passcode and refused to divulge it they can be held in jail until they release it, e.g. if your wife knows it. (There are many cases where people have been sentenced to years or decades in prison for not testifying)

If it is you not divulging your own passcode, then legally the judge can't give you contempt, but in reality they could give you contempt until you fought it through the appellate court. Contempt is a special type of thing - certainly here in Illinois you have no right to a jury trial on contempt charges. You're just fucked.

I believe judges can, in fact, hold a defendant for refusing to give up their own passwords, and that the contempt could be indefinite. This is a point of law that is not settled at the federal level yet, and at the state level it varies from jurisdiction to jurisdiction.

In one case, the appellate court at the federal level simply refused to hear the case that had been decided at the sate supreme court level.

https://www.reuters.com/business/legal/us-supreme-court-nixe...