[kinghajj]

With the safe analogy, I swear there's precedent that, if the security is a physical key, then a court can compel the owner to produce it. But if the safe uses a combination, the court cannot compel its divulgence, since that would violate the fifth amendment protections against being forced to testify against oneself. Encryption "keys", and the passwords from which they are commonly derived, are much more akin to combinations than to physical keys.

[happythomist]

I think there might be a circuit split on this issue, but IMO merely divulging a combination or encryption key is not "testimonial" (and therefore not a 5th Amendment violation) except insofar as it admits knowledge of the combination or key itself. But if police can establish separately that you know it, then the "foregone conclusion" exception applies.

If you can point to specific precedent that would be helpful.

[happythomist]

Did some more research on this; see this comment: https://news.ycombinator.com/item?id=23647018