User Guide

After activation, the display requests the user to input a 8-digit challenge. The user then enters a configurable 4-digit PIN. The card responds with a 6-digit response that is displayed for 20 seconds. In the last step the user enters the response into the interface that generated the challenge where it is verified.

Power On and Data Input

The activation differs from the data input. This might be confusing on first use.

Press (with thumb on the button and index-finger on the back) the power symbol until the characters 'CH____' are visible on the display. When the display does not activate, press with more power. 

Touch (soft physical contact with the surface) the numbers, ok or c with the index-finger. No pressure is required.

The different input methods are required to avoid accidental activation and save battery power.


This animation shows how the OCRA OTP card is used.



This diagram documents the possible input state transitions.


Avoid storing the OTP card in hot or cold places. Such environments may damage the battery powering the device.


This image shows the position of the battery for environmentally safe disposal of the device.