OpenUAT implements different authentication protocols from a user respectively application point of view. However, on implementation and wire-protocol level, most of these have now been unified with the newly developed Unified Auxiliary Channel Authentication Prococol (UACAP). UACAP can use the following interaction modes:
- input: The user acts as an information provider and causes common input to all authentication parties, for example by entering the same password/PIN or shaking both devices in the same hand.
- transfer: The user assists in transferring a message from one device to the other, for example by reading from the screen and entering the displayed string on the other device or by capturing a displayed 2D barcode with the camera of the other device.
- verify: The user acts as a verifier and compares the output of all authentication parties, for example by verifying that the strings displayed on both devices are equal or that audio tunes match.
These different modes distinguish protocol flow before and after the common key agreement phase:
