The Fifth Amendment to the US Constitution provides that no person shall be compelled in any criminal case to be a witness against himself. Ratified 1791. The “right to remain silent” in popular usage. In digital cases, the question is whether forced disclosure of a passcode or biometric unlock counts as compelled testimony, and the courts split on the answer.
What it means in practice
Passcodes and biometrics are treated differently. The dominant judicial position through 2025 is: an alphanumeric passcode is testimonial (your knowledge of it is the thing the government wants), and Fifth Amendment protection generally applies. A biometric unlock (face, fingerprint) is non-testimonial because it is a physical characteristic, not knowledge, so the Fifth Amendment generally does not block compelled use. The exceptions are real and circuit-dependent: the foregone-conclusion doctrine lets courts compel disclosure if the government already knows the device is yours and what is on it (US v. Doe, multiple circuits), and some state courts have ruled biometric compulsion unconstitutional under stronger state constitutions. Operational reality: alphanumeric passcode survives more scenarios than biometric unlock.
Who it affects, and how
Affects everyone subject to US criminal process or border inspection. Border agents at US ports of entry can demand devices and passcodes; refusal does not legally compel an agent to grant entry but does not authorize them to forcibly take the passcode either. The agent’s leverage is detention time, secondary screening duration, and (for non-citizens) entry refusal. Foreign nationals facing US asylum interviews, US person travelers facing CBP secondary screening, and US persons facing federal grand jury subpoenas have all litigated these questions in the past decade with mixed outcomes. The Beverly Hills case (US v. Apple, 2016) and the All Writs Act litigation that followed reshaped how Apple and Google design device security around the assumption of compelled-disclosure attempts.
What you can change today
Operational rule for any high-stakes situation: alphanumeric passcode of 10+ characters, never a 4 or 6 digit PIN, and biometrics disabled or set to a finger you do not normally use (so you can revoke under duress without explanation). Before any border crossing, restart the device so it boots in BFU state where biometric unlock is disabled until the first passcode entry. If a US lawyer is part of the trip plan, retain them before traveling, not after detention; the Sixth Amendment right to counsel does not extend automatically to border secondary screening, and asking for one is an awkward conversation rather than an enforceable right.