Sign-in and Session Recovery

Durable sign-in

Your initial iPhone sign-in uses your phone number and an SMS one-time passcode. After that, SemaFore keeps a device-bound, rotating renewal credential in protected local storage. It renews short-lived access in the background, reconnects, and retries one interrupted request without asking for another OTP during ordinary use.

A temporary problem reading secure storage or reaching the service does not by itself mean that you have been signed out. SemaFore retries bounded, recoverable failures before asking you to act.

Reauthenticate on the same device

If SemaFore asks you to verify again, or a recovery message calls for re_authenticate, sign in again with the same phone-number identity. This refreshes authentication without replacing the device registration.

Same-subject reauthentication preserves the device identity, local messages and groups, encrypted drafts and pending sends, and the encryption state used for existing conversations.

Before using a different phone-number identity

If this installation is bound to a different SemaFore subject, the app presents a separate confirmation before it can continue. This is re_register recovery, not ordinary sign-in.

Sign out versus destructive recovery

Ordinary same-subject sign-out and sign-in do not invoke the different-subject wipe. Destructive clearing is reserved for current-device retirement or an explicitly confirmed different-subject recovery.

See Device Lifecycle for retirement and re-registration, or Troubleshooting if the app displays an SF support reference.