# Welcome to Otpkey

Easy and convenient multi-factor authentication framework solution for enhanced security


# Otpkey Authenticator

Introducing the Otpkey Authenticator apps.

The Otpkey Authenticator app creates authentication credentials, such as OTP, Push-based authentication, and QR code-based authentication, to verify users' identities when needed. Similar apps include Google Authenticator and Microsoft Authenticator apps.

For example, if you use two-factor authentication on GitHub to enhance security, you need to use an OTP app on your mobile device such as the Otpkey Authenticator app.

The Otpkey Authenticator app is a multi-factor authentication app developed and distributed by Certchip as part of the OTPKEY authentication product line. This app is available on the following platforms and can be installed on your device for free through each of the stores below.

{% embed url="<https://play.google.com/store/apps/details?id=com.otpkey.authenticator&time=1>" %}
Android
{% endembed %}

{% embed url="<https://apps.apple.com/us/app/otpkey-authenticators/id6444123920>" %}
iOS, macOS, watchOS
{% endembed %}

{% embed url="<https://apps.microsoft.com/store/detail/otpkey-authenticator/XP9MCL9T4JFZ0B>" %}
Microsoft Windows
{% endembed %}

To help you quickly understand, we have attached the main screenshots of each app.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FAkdzvunybYAFcmchw83Y%2Fimage.png?alt=media&amp;token=c69777f3-76a3-4a87-9779-a6c0fee7a9a8" alt=""><figcaption><p>iPhone / iPad / Apple Watch</p></figcaption></figure>

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FlvJly5w9QbpITnhJyiqw%2Fimage.png?alt=media&amp;token=7326b5c3-a4fa-44a9-98ed-104e4b3f212e" alt=""><figcaption><p>Android</p></figcaption></figure>

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FoR4XE7a6sfOsLhzghmnu%2Fimage.png?alt=media&amp;token=ad099f0d-8ddc-4cb6-81e6-5789c422b580" alt=""><figcaption><p>OS X</p></figcaption></figure>

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FazmrIW3QiOEqLBzhEvqD%2Fimage.png?alt=media&amp;token=02911d16-f410-421e-8f72-d1953ff10884" alt=""><figcaption><p>Windows</p></figcaption></figure>


# OTP Credential Provider

Introducing the OTP Credential Provider app.

> This app has been developed and tested on Windows version 8 and later. The Microsoft Store provides it for Windows 10 or later, and if you want to use it on a version prior to Windows 10, download and install the installer from [www.otpkey.com](https://otpkey.com/#/windowsLogon).

The OTP Credential Provider app enhances the security of your Windows logon account.

No authentication server is required to use this function. You just need an OTP app installed on your mobile device (e.g. iPhone, Android phone, iPad, Apple Watch, etc.) that supports the standard TOTP, such as Google Authenticator, Microsoft Authenticator, Otpkey Authenticator, or other commonly used OTP apps.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FeEJ4VHsFeIusb4zNkXqV%2Fimage.png?alt=media&amp;token=6bb3c616-c422-4d0b-96aa-7e0e4e381cc2" alt=""><figcaption><p>OTP Credential Provider with Otpkey Authenticator</p></figcaption></figure>

This function works at the same security level as the default PIN number in Windows, but the fact that the value changes every 30 seconds makes it very secure.

The fact that the OTP code that changes every 30 seconds can only be checked on your mobile device paired with your PC will keep you safer.

You can secure your Windows logon account using OTP credentials by installing the OTP Credential Provider on your Windows system in just a few minutes.

We will outline the process for installing the OTP Credential Provider, do we encourage you to get started now.

The procedure for setting up OTP credentials for your Windows account is as follows.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2F1jCilVwil6zm4GRZNutg%2Fimage.png?alt=media&amp;token=43d96d69-629f-4b05-b022-11c47f5ea39a" alt=""><figcaption></figcaption></figure>

**PROCESS-1: Install the OTP Credential Provider app on your Windows**

Visit the Microsoft Store on your Windows and search for "OTP Credential Provider" or visit the following link to install the OTP Credential Provider app from the Microsoft Store.

{% embed url="<https://apps.microsoft.com/store/detail/otp-credential-provider/XPDNVLZZ10ZN6V>" %}

You can find the "OTP Credential Provider" app in the Microsoft Store as follows and you can safely and easily install it on your Windows system.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2Fmwy652FwTlZzC72yHwcJ%2Fimage.png?alt=media&amp;token=4427733e-87b8-46e4-9866-197a824a4322" alt=""><figcaption></figcaption></figure>

After installation is complete, you can find the OTPKEY Credential Provider launch icon on the desktop or in the Programs Menu.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2Fkt7aml54TYOX1HZvP3by%2Fimage.png?alt=media&amp;token=a8b09724-685e-4fc2-9e52-e3b19b6f67c0" alt=""><figcaption><p>OTPKEY Credential Provider on Desktop</p></figcaption></figure>

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FlxjZPMEIdANHg38U3Db6%2Fimage.png?alt=media&amp;token=94ab315d-789a-4214-ad6b-c2683a6e54ca" alt=""><figcaption><p>OTPKEY Credential Provider on Programs Menu</p></figcaption></figure>

**PROCESS-2: Install the OTP app on your mobile device**

This process can be skipped to the next step if you already have OTP app installed on your mobile device. However, if you want to use the Otpkey Authenticator app, you can install it from the following app stores.

{% embed url="<https://play.google.com/store/apps/details?id=com.otpkey.authenticator>" %}

{% embed url="<https://apps.apple.com/app/otpkey-authenticators/id6444123920>" %}

For convenience, this article assumes that the Otpkey Authenticator app is installed on your mobile device. However, we believe that the process is not very different even if you use other OTP apps.

**PROCESS-3: Register OTP authentication device**

This process is for registering the OTP authenticator app (also called OTP authentication device) installed in **PROCESS-2** to the Otpkey Credential Provider installed in **PROCESS-1**.

When Otpkey Credential Provider is executed, the screen below is displayed. Click '**STEP 1 : Device Registration**' with the mouse on the program screen executed.

Since Windows administrator privileges are required to register an authentication device, a message window requesting administrator permission is displayed as follows. Click the \[Yes] button to run with administrator permission granted.

If the program has already been run with administrator permission, the administrator permission request message window will not appear, so please disregard this explanation.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FGzox8CBhEbuHMVOy9hRq%2Fimage.png?alt=media&amp;token=6415a0ba-2b85-4424-b332-42f6ad0ed467" alt=""><figcaption></figcaption></figure>

The screen presented below is a screen run with administrator privileges. The title of the program is accompanied by the word Administrator.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FVoA9oHL5tbTEGMNk6VaJ%2Fimage.png?alt=media&amp;token=6aedf506-f3e7-4548-880b-0f966f6e4408" alt=""><figcaption></figcaption></figure>

The following screen is an example of Device Registration screen. The QR code displayed contains a format that can be scanned by an OTP Authenticator apps.&#x20;

**a) Please scan a displayed QR code using the OTP Authenticator app on your mobile device.**

**b) If the scan is successful, enter the displayed OTP code into the 'OTP Code' field on the PC screen's 'Device Registration' dialog. Then, click the 'Register' button to complete the registration processed.**

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FG3dVtAg8FoBspffif8If%2Fimage.png?alt=media&amp;token=f4b0b927-a70d-4d46-afd1-e49cd3532f0a" alt=""><figcaption></figcaption></figure>

If you see the following screen on your Otpkey Credential Provider, it means that your device has been registered successfully.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FB8zMS6bhUPQBmW2Wemny%2Fimage.png?alt=media&amp;token=920970ec-c198-42e7-9e27-28bbff05a0ff" alt=""><figcaption></figcaption></figure>

Your OTP Authenticator app (also known as your OTP authentication device) is now registered with your Windows account.

**PROCESS-4: Credential Enrollment**

This is the process of enrolling one-time password (OTP) credentials to your Windows user account. These credentials are then used for logging in to the Windows system using the registered OTP.

Click "**STEP 2 : Credential Enrollment**" on the OTP Credential Provider screen. On the OTP Credential Provider screen, a message window indicating that you need to log in again appears as follows.

You can go to the Windows logon screen by clicking the \[Yes] button. However, Windows will log off, so if you have unsaved data, please save it safely before proceeding.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FZ6IXXfafeQUNWgOBehSA%2Fimage.png?alt=media&amp;token=7289b6db-1c30-4a19-ac98-f4ef7506a3b8" alt=""><figcaption></figcaption></figure>

You can find "**Sign-in options**" on the Windows logon screen. You can show the currently available login methods as buttons. Among these buttons, if you select the "**OTPKEY Credential**" button (lock-shaped icon button), the following OTPKEY Credential Provider screen is displayed. When enrollment is successful, Windows will log on with OTP credentials.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FLVNYrGUthjiwTrvDCqbP%2Fimage.png?alt=media&amp;token=89e68358-2024-4ca5-9c3f-b826e70be27c" alt=""><figcaption></figcaption></figure>

When all procedures are completed, the screen of the OTP Credential Provider program will display "**CONGRATULATIONS**" as follows. This means that the OTP Authenticator and OTP Credentials are associated with your Windows account.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FWXuS2fld3NLzX1L0Bgwo%2Fimage.png?alt=media&amp;token=985e79b0-e2e0-4c99-b657-f5b573656a14" alt=""><figcaption></figcaption></figure>

**FINAL : Use OTP for Windows login**

If your OTP Authenticator and OTP Credential have been linked to your Windows account through the above procedure, you can use the OTP Credential Provider on your Windows logon screen as follows. Now you can log in to Windows in a safe and convenient way by using your OTP credentials.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2F7EpClFlEP6y0ZMsn57A6%2Fimage.png?alt=media&amp;token=0625cc3a-73a0-469e-824c-b32901ac6968" alt=""><figcaption></figcaption></figure>

Thank you for taking the time to read through all the above information. We strive to provide you with even more helpful information in the future.


# OTP Auth Login

Introducing the OTP Auth Login app.

> This app is developed and tested on Mac OS version 10.14 (Mojave) and later versions, and installation images are provided. Also, both Apple Silicon and Intel are supported.

The OTP Auth Login app enhances the security of your Mac login account.

No authentication server is required to use this function. You just need an OTP app installed on your mobile device (e.g. iPhone, Android phone, iPad, Apple Watch, etc.) that supports the standard TOTP, such as Google Authenticator, Microsoft Authenticator, Otpkey Authenticator, or other commonly used OTP apps.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FNc6B6OP6VWW5CrtmuA6k%2Fimage.png?alt=media&amp;token=6adba05f-efe6-443c-8d00-244f9f34700e" alt=""><figcaption><p>OTP Auth Login with Otpkey Authenticator</p></figcaption></figure>

Enhance your Mac login security. You can use the OTP Auth Login on your Mac login screen right now.

This app provides a secure and easy way to add OTP (One-time Password) authentication to your Mac logins.

The fact that the OTP code that changes every 30 seconds can only be checked on your mobile device paired with your Mac will keep you safer.

You can secure your Mac login account using OTP credentials by installing the OTP Auth Login on your Mac in just a few minutes.

We will outline the process for installing the OTP Auth Login, do we encourage you to get started now.

The procedure for setting up OTP credentials for your Windows account is as follows.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FmSfRE018Kl0oluNEtbOe%2Fimage.png?alt=media&amp;token=62b30ad4-0ebc-41f4-b0c5-3e7ea55eee48" alt=""><figcaption></figcaption></figure>

**PROCESS-1: Install the OTP Auth Login app on the Mac**

Visit the address specified below and click \[Download for macOS] to download the installation disk image file.

{% embed url="<https://otpkey.com/#/authlogin?category=mac>" %}
<https://otpkey.com/#/authlogin?category=mac>
{% endembed %}

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2Fst6Ax4Hb92xDhhxc3uK6%2Fimage.png?alt=media&amp;token=97f3e73d-9a79-435e-9396-8f72badbc911" alt=""><figcaption><p>Download for macOS</p></figcaption></figure>

You can find the "OTPAuthLoginInstaller.dmg" file in your Downloads folder.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2Fx4twqzAjCTgrNgK9aUfF%2Fimage.png?alt=media&amp;token=a91076ec-e23b-4927-88cc-9b71ce2b162a" alt=""><figcaption></figcaption></figure>

Open the "OTPAuthLoginInstaller.dmg" file and the following window will open.

![](https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FSw31W5K1vs97GJLbpfht%2Fimage.png?alt=media\&token=03c268f1-4de9-406b-929f-f59036cdf420)

You can find the "OTP Auth Login.pkg" icon in the opened "OTP Auth Login Installer" and double-click on it to launch it. You can use it to install the "OTP Auth Login" app on your Mac.

<img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FssAkwFrlTCiy0F9bots5%2Fimage.png?alt=media&amp;token=2963893c-d266-4aef-9bd9-73094ffc1b41" alt="" data-size="original">

After installation is complete, you can find the following "OTP Auth Login" app in your Applications. You can use this app to register OTP credentials on your Mac.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FPCyYthqdiwuyP1Vxg8Rx%2Fimage.png?alt=media&amp;token=8279146c-31e1-4339-9166-1fe37f215681" alt=""><figcaption></figcaption></figure>

**PROCESS-2: Install the OTP app on your mobile device**

This process can be skipped to the next step if you already have OTP app installed on your mobile device. However, if you want to use the Otpkey Authenticator app, you can install it from the following app stores.

{% embed url="<https://apps.apple.com/app/otpkey-authenticators/id6444123920>" %}

{% embed url="<https://play.google.com/store/apps/details?id=com.otpkey.authenticator>" %}

For convenience, this article assumes that the Otpkey Authenticator app is installed on your mobile device. However, we believe that the process is not very different even if you use other OTP apps.

**PROCESS-3: Register OTP authentication device**

This process is for registering the OTP authenticator app (also called OTP authentication device) installed in **PROCESS-2** to the OTP Auth Login installed in **PROCESS-1**.

When OTP Auth Login is executed, the screen below is displayed. Click '**STEP 1 : Device Registration**' with the mouse on the program screen executed.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FoHa6UGZ4B5M8Il5b1I47%2Fimage.png?alt=media&amp;token=a900c7f5-f6dc-434b-9ac1-99626ce4a1a3" alt=""><figcaption></figcaption></figure>

The following screen is an example of Device Registration screen. The QR code displayed contains a format that can be scanned by an OTP Authenticator apps.&#x20;

**a) Please scan a displayed QR code using the OTP Authenticator app on your mobile device.**

**b) If the scan is successful, enter the displayed OTP code into the 'OTP Code' field on the Mac screen's 'Device Registration' dialog. Then, click the 'Register' button to complete the registration processed.**

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FihMPrUKGtAphDfNPsLMr%2Fimage.png?alt=media&amp;token=c14bf4ea-8e48-495c-a0fa-0f2746050c74" alt=""><figcaption></figcaption></figure>

If you have registered the authentication device (e.g. OTP Authenticator App) through the above process, you can install the OTP Auth Plugin on your Mac as shown below.

Click the \[Yes] button to install the OTP Auth Plugin on your Mac.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2F7YKXVXRrMYBdNiOgphv0%2Fimage.png?alt=media&amp;token=db689026-eb22-441d-b818-0a4c8b9ecf85" alt=""><figcaption></figcaption></figure>

If the authentication plug-in installation process is completed successfully, you will see the following OTP Auth Login screen.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FEBH4PQi1G4vTKqIzm3Lf%2Fimage.png?alt=media&amp;token=071b62c4-a76b-4611-bdd0-93809c12aab5" alt=""><figcaption></figcaption></figure>

Your OTP Authenticator app is now registered and the plug-in has been successfully installed on your Mac. After restarting your Mac, you can proceed with the enrollment of your OTP credentials to your Mac account.

**PROCESS-4: Credential Enrollment**

This is the process of enrolling OTP (One-time Password) credentials to your Mac user account. These credentials are then used for logging in to the Mac using the registered OTP.

Click "**STEP 2 : Credential Enrollment**" on the OTP Auth Login screen. On the OTP Auth Login screen, a message window indicating that you need to Mac log in again appears as follows.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2F48sYKrKfp8Pfja4DlwrL%2Fimage.png?alt=media&amp;token=1c2b366e-beff-4e0a-954b-f9f53ebf8531" alt=""><figcaption></figcaption></figure>

**Please restart your Mac.**

![](https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FjUhwderseoLwEelLgi4P%2Fimage.png?alt=media\&token=cb4c8461-f207-4b03-b780-84cab3ee7ea8)

After restarting your Mac, you will see the OTP Auth Login as shown below in the Mac login process.

> Note: The smartphone image shown below is for illustrative purposes only and will not be displayed on the login screen.

Entering the OTP code displayed on the registered authentication device, click the \[Enroll] button to register your OTP credentials to your Mac login account.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FqQrIen2WXJU78CszugtF%2Fimage.png?alt=media&amp;token=e18ff02b-fe69-486f-aff6-d13054f39404" alt=""><figcaption></figcaption></figure>

After completing all the procedures, the OTP Auth Log app will show the "CONGRATULATIONS", indicating that your OTP authenticator and OTP credentials are now associated with your Mac login account.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FEGLn43RvSjaklTyFkb5z%2Fimage.png?alt=media&amp;token=38df5a45-4d0f-46fc-ae61-f026e49e5307" alt=""><figcaption></figcaption></figure>

**FINAL : Enhance your Mac login security**

If your Mac login account, OTP Authenticator, and OTP Credential have been linked through the above procedure, you can use OTP Auth Login during the Mac login process.

Now, you have enhanced your Mac login security by using OTP (One-time Password) security plug-in provided by the OTP Auth Login app.

> Note: The smartphone and watch image shown below is for illustrative purposes only and will not be displayed on the login screen.

<figure><img src="https://2850472781-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FQuLCfwyWRZJr5B0g9BZx%2Fuploads%2FsCRJYuYDKiANjLDuIZ1v%2Fimage.png?alt=media&amp;token=6713862b-eb6e-42db-a95e-3df4e0880cec" alt=""><figcaption></figcaption></figure>

Thank you for taking the time to read through all the above information. We strive to provide you with even more helpful information in the future.

**Note :**

OTP Auth Login does not alter or break other login authentication plugins already installed on your Mac. This app works at the very end of other login authentication plugins. If you want to log in only with OTP authentication without using password authentication when logging in to your Mac, you can bypass the password input by using the automatic login function provided by Mac. However, this is for reference only.