HumanCheck

HumanCheck is two-factor authentication for people. Pair with someone you trust using a shared secret. HumanCheck securely derives relationship material on each iPhone. You each choose a different HumanCode, confirm that both phones agree, and save the relationship locally. Later, when you need confidence that you are speaking with the same person, exchange your rotating six-digit HumanCodes. Each phone shows which code to say and which code to expect from the other person. PRIVATE BY DESIGN - No accounts - No phone number or email verification - No backend or cloud synchronization - No advertising, analytics, or tracking - No third-party dependencies - HumanCodes work completely offline after pairing SECURE LOCAL STORAGE Relationship keys are stored in the iPhone Keychain (an encrypted software database stored on your device's file system) and remain bound ONLY to that device. Your friend's names and non-secret relationship metadata stay in local app storage. Shared secrets used to generate the pair are not retained after pairing. OPTIONAL APP PROTECTION You can require Face ID, Touch ID, or the device passcode before HumanCheck displays your Humans and HumanCodes. HumanCheck also covers sensitive content when the app becomes inactive. IMPORTANT LIMITATIONS A matching HumanCode shows that both devices possess the same previously established relationship material. It does not prove legal identity, prove who is holding an unlocked phone, or protect against someone who participated in or observed the original pairing. Pair privately with a person you already trust. If a device is lost, erased, replaced, or a relationship is removed, pair again in person or through another trusted channel.