Courts across the United States have applied Fifth Amendment protections to passcodes, as long as those passcodes are not a foregone conclusion. In order for a court to determine that a passcode is a forgone conclusion, and thus not testimonial in nature, the prosecution must show that they knew the existence, possession, and authenticity of the evidence that would be discovered by the compelled passcode, before the passcode is compelled. The foregone conclusion doctrine was established, and had been used, to balance the need of law enforcement to gather incriminating evidence while still protecting defendants’ Fifth Amendment rights. In 2016, the Florida Second Court of Appeals took the forgone conclusion doctrine to an extreme in State v. Stahl, by expanding the foregone conclusion doctrine and finding that evidence must be significantly testimonial in order for it to be protected by the Fifth Amendment. If other courts follow the Stahl decision, it would mean the end of the balance that the foregone conclusion has provided as well as all Fifth Amendment protections to encryption.
Jesse Coulon, Privacy, Screened Out: Analyzing the Threat to Individual Privacy Rights and Fifth Amendment Protections in State v. Stahl, 59 B.C.L. Rev. E. Supp. 225 (2018), http://lawdigitalcommons.bc.edu/bclr/vol59/iss9/13