• What are the meaning of the LED indication on OpenTurnKey?


LED = All-off

OpenTurnKey State:

    Sleep (Idle) / Power-off (Battery too low)


LED = Green-on (Steady)

OpenTurnKey State :

    (1) OpenTurnKey unlocked (Power-on)

    (2) Fingerprint capture / matching success (Run-time)


LED = Red-on (Steady)

OpenTurnKey State :

    (1) OpenTurnKey locked (Power-on)

    (2) Fingerprint capture / matching failed (Run-time)

    (3) Charging (Power-off)


LED = Green-on (Fast Blink)

OpenTurnKey State :

    OpenTurnKey unlocked & low battery (Power-on)


LED = Red-on (Fast Blink)

OpenTurnKey State :

    OpenTurnKey locked & low battery (Power-on)


* Red-on slowly blink only occurs in system error, not often seen, and the number of blink indicated its error code.


LED = Blue-on (Slowly Blink)

OpenTurnKey State :

    OpenTurnKey standby (Run-time)


LED = Pink-on (Slowly Blink)

OpenTurnKey State :

    NFC communication (Run-time)


LED = Green/Red-on (Interleaved)

OpenTurnKey State :

    Waiting for finger touch (Run-time)


LED = Green-on (Slowly Blink)

OpenTurnKey State :

    Authenticated or data ready (Run-time)


LED = Blue-on (Blink twice)

OpenTurnKey State :

   Power-off notice (Run-time)

  • How long does it take to have an OpenTurnKey fully charged?

It takes about 30 minutes to get an OpenTurnKey fully charged by a Qi charger.


Do not leave an OpenTurnKey on a charger for over an hour. Even most Qi chargers and the OpenTurnKey Qi receiver has protection circuits to stop charging after battery is fulled. Some badly designed Qi charger may not stop the power output which will increase the temperature significantly and eventually damaged the OpenTurnKey.

The key point is to use a compatible Qi charger. A compatible Qi charger should be able to couple with OpenTurnKey easily and the temperature will always remain low.

  • How long can the battery of OpenTurnKey last?

A fully charged OpenTurnKey can work for approximately a little more than 1 hour continuously. Assuming each operation takes 15~20 seconds, it roughly equals to 180~240 operations. If a user makes 5~10 transactions everyday, a fully charged OpenTurnKey can be used for several weeks before battery runs out.


The battery of an OpenTurnKey under sleep mode can last for months. You should charge OpenTurnKey when it shows a low-power indication. 

If you are going to keep an OpenTurnKey in a safe place without using it often, do not forget to check its battery every 3 month and make sure the battery level remains more than 50 %. 

An OpenTurnKey keeps in uncharged state for a long time may causing the battery not being able to be charged anymore.

  • Why Is OpenTurnKey Secure?

OpenTurnKey is the most secure way to keep the private key safe, because the private key is randomly generated by the hardware when it is minted and a user can use any one level 5 child key out of ~2^155 child keys.

OpenTurnKey can only communicate with external devices via limited NFC commands. The private key will stay only in the hardware unless a user choose to export one from a specific child key. 

Even though, OpenTurnKey is very secure in keeping the private key safe, a user must always be careful to choose a trusted party in making a transaction which will sign a signature with OpenTurnKey. Since the singing process is not visualized by the user, a user should only give out signatures to trusted parties or double validate the transaction result after transaction is made.

  • How Can I Trust OpenTurnKey?

  • Why Is the Package of OpenTurnKey So Simple?

We like eco-friendly product. There are too many products that has been over packaged. Those plastics, paper boxes, and printing costs a lot of money and ends up in garbage. We do not want to waste resources and harm the earth, so we choose to provide our product in a plain simple way with only necessary protection. All of the user's guide, warranty, and service terms can be found on our website and keeping updated through time. This is way more efficient and fits the purpose of crypto economy.

  • How Many Crypto-currencies Does OpenTurnKey Support?

The app we provided only support Bitcoin at the moment. Our purpose is to help people to transit to crypto economy not to encourage speculation. People might hold different visions and expectations on crypto-currencies. We respect them, but we believe the most important thing is to have everyone on the same page. Bitcoin has been widely adopted and gone through the market validation. It may have its limit to play the role of global money, but we believe together we can find a way to improve things.

  • Why Does Not OpenTurnKey Support Alt-coins? 

This has to do with our mission and belief. We created OpenTurnKey for the purpose of promoting a global crypto economy. We believe that a decentralized global money replacement is needed for this new economy, so what we really need is a new money, not more investment products.

Bitcoin is the start of this economy revolution. It might not be the ultimate answer, but we believe we will improve the new 'money' from there. 

Nevertheless, OpenTurnKey is capable to work with many alt-coins as long as they are based on the same ECDSA algorithms as Bitcoin used. What OpenTurnKey does is to keep the private key safe and generate (ECDSA) signatures with the private key. Therefore, it is possible to develop applications for OpenTurnKey to work with alt-coins. 

We have a roadmap to publish the OpenTurnKey NFC protocol publicly for developers to develop all kind of applications, not only for cryptocurrency but also in solving real world problem together with the crypto technology and cryptocurrency, such as using OpenTurnKey as subway ticket, ignite a car, or open a door, etc.

  • Can I Back Up or Duplicate an OpenTurnKey?

You cannot backup or duplicate an OpenTurnKey. Each OpenTurnKey contains a unique master key. However, you can export a WIF (Wallet Importable Format) private key of a child key and keep that exported WIF private key as a backup to your crypto assets. Please note that, it will be your own responsibility and risk to keep that exported private key safe. 

For how to export the WIF private key of a child key, please check our user guide video in the 'Guide' page.

  • Can I Upgrade the  OpenTurnKey Firmware?

No, we design OpenTurnKey to be sealed off after it is minted. We believe this provides the most secure protection. An upgrade procedure done by users themselves could leads to unexpected hacking risk. People may distribute malicious fake firmware as an attack. 

Just like paper currency which often to be replaced periodically, we may improve and upgrade OpenTurnKey in later releases, but for those which have already been released, they should stay as is. And that is why we provide a free upgrade replacement for each purchase. Check it out in the 'Terms' page. 

  • What Can I do If Lost or Damaged My OpenTurnKey? (Not answered yet)

  • Can I Make a Payment with OpenTurnKey Only ? (Not answered yet)

  • How To Make a Physical Transition of OpenTurnKey? (Not answered yet)

  • How To Validate an OpenTurnKey?


A valid OpenTurnKey is made of with a random generated 'Master' key and a level 5 derivative child key which is selectable by the users. To prove a derivative child key is truly derived from the master key, a user can get the master public key, derivative public key, key path information through 'Crypto Economy' app and validate those information on the public website, https://bip32.org. Here are the steps of validation,

1. (In a Browser) Go to this URL, https://bip32.org/. User will see a public opensource tool 'BIP32 Deterministic Key Generator'. 

2. (In a Browser) In the 'Derive From' field, click on the button 'BIP32 Key', and in the 'Derivation Path' field, choose 'Custom'.

3. Turn on the 'OpenTurnKey' to be validated and 'Crypto Economy' (App).

4. (In Crypto Economy App) Go to the "OpenTurnKey" page and select the function 'Full Public Key Information" in the menu.

5. (In Crypto Economy App) Authorize 'OpenTurnKey' with fingerprint or PIN code and the full public key information of the 'OpenTurnKey' will be revealed.

6. (In Crypto Economy App) Copy your master public key in the 'Full Public Key Information' and (In a Browser) paste it into the 'BIP32 Extended Key' field.

7. (In Crypto Economy App) Copy the 'Derivative Path' and (In a Browser) paste it to the 'Custom Path'.

8. (In a Browser) The 'BIP32 Deterministic Key Generator' tool will calculate the derivative key based on the master public key and derivative path you entered. The user can check if the derivative public key matched with the key shown in the App and also the derived Bitcoin address should be the same the the Bitcoin address of the 'OpenTurnKey'.

* bip32.org is a open source project hosted on Github. It is an implementation of BIP32 protocol using JavaScript and its code is running on user's computer.

** All of the above validation information, master public key, derivative public key, derivative path, cannot be used in reversal calculation to the private key to make a transaction. There is not any risk to validate these information with the bip32.org tool. However, we still strongly recommend you not to share these information publicly in not really necessary.

  • How To Decode a Raw Transaction? (Not answered yet)

To be completed