The 5th amendment protects against forced testimony, not against compulsion to provide evidence. You can refuse to testify against yourself, you cannot refuse to comply with a valid search warrant.
I would argue that all evidence is really just information. Once again, the old lines dividing one category from another become blurred.
You're compelled to provide access. You could probably make a legitimate case for not actually revealing the password if you provided access for them.
It would be interesting to know if there was ever a hybrid case where there was a password-protected door with a numeric keypad, and someone refused to give the pw. I'd assume in a case like that, however, the cops would just smash shit out of it.