The OnlyKey Firmware runs on the OnlyKey itself and provides the core functionality of OnlyKey.
Edit me


This is the official firmware for OnlyKey - The Two-factor Authentication & Password Solution.

OnlyKey can be purchased here: OnlyKey order


OnlyKey started out with a successful Kickstarter in 2016: OnlyKey Kickstarter Page


There are two available version of the OnlyKey firmware:

OnlyKey Standard Edition The full featured OnlyKey firmware comes pre-installed on the OnlyKey (Ships to US).

OnlyKey International Travel Edition The encryption free OnlyKey firmware comes pre-installed on the OnlyKey (Ships Internationally).

For more information on the difference between the two versions see the OnlyKey FAQ.

Note: User’s can change the edition of their OnlyKey anytime by loading open source firmware using instructions in Quick Start Guide.

Find out more about Plausible Deniability and how to travel internationally with digital privacy intact here!

Geting Started

Step by step setup instructions are provided in the OnlyKey Quick Start Guide


OnlyKey is currently released as a fully functional Beta. Development will be ongoing as additional features are added. To see a list of current and future features see OnlyKey Features section of the OnlyKey User’s Guide


Check out the OnlyKey Support Forum.

Check out the OnlyKey Documentation


Check out the OnlyKey Libraries Here.

A special thanks to those who made this project possible:


Arduino -

Yubico -

pagong/arduino-yksim -

lucadentella/ArduinoLib_TOTP -


Cathedrow/Cryptosuite -

Frank Boesing -

Yohanes -

Ken MacKay -

Rhys Weatherley -

Mbedtls -

Defragster -

For information on installing libraries, see:

Legal things

Cryptography Notice

This distribution includes cryptographic software. The country in which you currently reside may have restrictions on the import, possession, use, and/or re-export to another country, of encryption software. BEFORE using any encryption software, please check your country’s laws, regulations and policies concerning the import, possession, or use, and re-export of encryption software, to see if this is permitted. See for more information.

The U.S. Government Department of Commerce, Bureau of Industry and Security (BIS), has classified this software as Export Commodity Control Number (ECCN) 5D002.C.1, which includes information security software using or performing cryptographic functions with asymmetric algorithms. The form and manner of this distribution makes it eligible for export under the License Exception ENC Technology Software Unrestricted (TSU) exception (see the BIS Export Administration Regulations, Section 740.13) for both object code and source code.

The following cryptographic software is included in this distribution:

                  "MBED TLS PROJECT" -
                  "MICRO-ECC PROJECT" -
                  "ARDUINOLIBS PROJECT" -
                  "YUBICO-C PROJECT" -

For more information on export restrictions see:


OnlyKey Firmware on Github OnlyKey Libraries on Github