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Novaz AuthenticatorGET

CEX.IO 2FA: how to set up an authenticator app

By the Novaz team · Updated October 29, 2026
Novaz steps checked against version 1.0.5

On this page
  1. Turn on 2FA on the CEX.IO website
  2. Or turn it on in the CEX.IO app
  3. The secret code is your backup
  4. When CEX.IO asks for a code
  5. If CEX.IO rejects your code
  6. Changing phones
  7. If you lose your authenticator
  8. Official CEX.IO help

CEX.IO is a cryptocurrency exchange, so the account holds money, and CEX.IO treats two-factor authentication (2FA) that way: you can't withdraw anything until it's on (CEX.IO). It offers two methods, a code from an authenticator app or a code by text message, and suggests turning on both. Text messages aren't offered in every country (CEX.IO).

CEX.IO's help names Google Authenticator, but any authenticator app works the same way. This guide uses Authenticator App - Novaz on iPhone. Know this first: CEX.IO gives no list of backup codes. Your safety net is the key it shows during setup.

How we checked this guide: the CEX.IO steps come from CEX.IO's own help center, linked below, which we read on October 21, 2026. We haven't tested them on a CEX.IO account, so a label may differ slightly. The Novaz steps are checked against the app, version 1.0.5.

Turn on 2FA on the CEX.IO website

The website shows a QR code, so it's the easier route (CEX.IO):

  1. Sign in on the CEX.IO website, click your profile icon and choose Security.
  2. In the Two-Factor Authentication (2FA) section, click Enable next to Authenticator App.
  3. Read the security warning and click Continue.
  4. CEX.IO emails a confirmation code to your account's address. Enter it and click Next.
  5. CEX.IO shows a QR code and the Authenticator Secret Code. Save the secret code somewhere safe before you go on (see below).
  6. In Novaz, tap +, then Scan QR code, and point the camera at the screen. Then click Next on CEX.IO.
  7. Type the 6-digit code from Novaz in the 2FA code field and click Enable.

Or turn it on in the CEX.IO app

The mobile app's steps don't show a QR code at all, only the secret code with a button to copy it (CEX.IO):

  1. In the CEX.IO app, tap the profile icon at the top left, then Security.
  2. Choose 2FA with Auth app.
  3. Copy the secret code and save it somewhere safe.
  4. In Novaz, tap +, then Enter key manually. Type CEX.IO as the Service, add your email under Account if you like, and paste the code as the Setup key. See What is a 2FA setup key?
  5. Enter the 6-digit code from Novaz in the CEX.IO app.

CEX.IO says its codes are 6 digits and change every 30 seconds, which is what Novaz uses for a typed key. Novaz needs the key to be at least 16 characters. CEX.IO doesn't say how long its key is, so if Novaz won't accept it, use the website and scan the QR code instead.

The secret code is your backup

CEX.IO calls the setup key the secret code, the backup key or the backup code. With it, you can add CEX.IO to an app again after a lost phone or a deleted app, without contacting support (CEX.IO).

That matters with Novaz unless you've turned on iCloud backup or exported a backup file, because otherwise its keys stay only on your iPhone. Keep the key in a password manager or on paper, away from the phone. Anyone who has it can make your codes.

When CEX.IO asks for a code

You enter a code each time you sign in, after your password, in the app or on the website. That includes signing in with Google. If you have both methods on, CEX.IO asks for the authenticator code by default. Sign in with another method lets you switch to a text message (CEX.IO).

If CEX.IO rejects your code

CEX.IO's troubleshooting page lists three causes for authenticator codes (CEX.IO):

  • The phone's clock is off. On iPhone, open Settings > General > Date & Time and turn on Set Automatically. Novaz warns you when the clock is 15 seconds or more off.
  • The code expired as you typed it. Enter a fresh one right away.
  • You used an old entry. Turning 2FA off and on can leave a stale CEX.IO entry. In Novaz, open it and tap Remove account.

More causes are in Authenticator code not working?

Changing phones

CEX.IO's way needs the old phone to still work (CEX.IO). Sign in, go to Security, click Disable next to Authenticator App, and confirm with a code. Then click Enable and set it up again on the new phone, saving the new backup key. Finally, delete the old CEX.IO entry from the old phone.

Disabling 2FA freezes withdrawals for 48 hours, so plan around it. If you saved your key, typing it into Novaz on the new iPhone also works, and so does restoring Novaz from iCloud backup or a backup file. See How to transfer your authenticator app to a new iPhone.

If you lose your authenticator

If you have the backup key, add it to Novaz on any iPhone with Enter key manually and sign in as usual. If you also set up text messages, you can sign in that way.

Without either, CEX.IO's answer to a missing key is blunt: "Unfortunately, neither do we" (CEX.IO). You can still ask it to reset 2FA (CEX.IO):

  1. On the website, click Sign In and enter your email and password.
  2. On the 2FA screen, click Lost your authentication device. With both methods on, click Sign in with another method first, then choose Lost authentication device.
  3. Read the warning, click Continue, and enter the code CEX.IO emails you.
  4. Fill in the form: your name, date of birth, home address and details of your latest transactions. Then complete a face check and upload a valid passport, national ID card or driver's license.

The review can take up to 48 hours, and CEX.IO emails you the result. It may ask for more details by email or live chat. Once 2FA is reset, set it up again. More in Lost the phone with your authenticator app?

Official CEX.IO help

More guides: Crypto exchanges and wallets