Bithumb 2FA: how to set up an authenticator app (Google OTP)
By the Novaz team · Updated October 29, 2026
Novaz steps checked against version 1.0.5
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Bithumb (빗썸) is a South Korean cryptocurrency exchange. Every account starts with a second check by phone: a KakaoTalk message, a text message or an automated call to the number you registered. You can swap that for an authenticator app, which Bithumb calls Google OTP 인증 (Google OTP verification). Once it's on, the code from the app is what you type for sign-in and for anything that moves your assets (Bithumb).
Bithumb's help is only in Korean, so labels appear here in Korean with our translation. The steps use Authenticator App - Novaz on iPhone, but any authenticator app works the same way.
How we checked this guide: the Bithumb steps come from Bithumb's own help center articles and their screenshots, linked below, which we read on October 21, 2026. The help center blocks automated page requests, so we read the same articles through its public article feed on support.bithumb.com. The articles are in Korean and the translations are ours. We haven't tested the steps on a Bithumb account, so a label may differ slightly. The Novaz steps are checked against the app, version 1.0.5.
One channel at a time
Bithumb's 보안센터 (Security Center) has a section called 2채널 인증 등록 (2-Channel Verification). It holds two options, and only one can be active (Bithumb):
- 알림톡(SMS) / ARS 인증: a code by KakaoTalk or text message, or an automated phone call. This is the default for new accounts.
- Google OTP 인증: a 6-digit code from an authenticator app.
Choosing one switches the other off. So the authenticator app doesn't add a layer on top of the phone check: it takes its place for trades, transfers and other actions that change your balance.
Turn on Google OTP
- Open the Security Center.
- On a computer: click your name at the top of bithumb.com, then 보안센터 (Security Center) under 설정 (Settings).
- In the Bithumb app: tap 더보기 (More) in the bottom menu, then 고객센터 (Customer Center), then 보안센터 (Security Center).
- Under 2채널 인증 등록, select 사용하기 (Use) next to Google OTP 인증.
- Bithumb shows a barcode (QR code) and, below it, a 16-character key for when you can't scan. In Novaz, tap +, then Scan QR code, and point the camera at the code on your computer screen.
- If you're setting up in the Bithumb app on the same iPhone, scanning won't work. Either take a screenshot and use + > Choose a photo in Novaz (how that works), or tap 복사 (Copy) next to the key, then in Novaz tap +, then Enter key manually, and paste it as the Setup key. See What is a 2FA setup key?
- Next to 인증번호 (verification code), select 인증요청 (Request code). Bithumb sends a code to the phone number on your account. Type it in.
- In Google OTP 인증번호 (Google OTP code), type the 6-digit code from Novaz.
- Select 확인 (Confirm).
The Security Center should then show 사용중 (In use) next to Google OTP 인증.
Bithumb's pages only name Google Authenticator and don't say whether other apps are supported. The setup itself is the usual QR code and text key that any time-based authenticator app reads.
No backup codes
Bithumb's help doesn't mention backup or recovery codes for Google OTP. Its documented fallback is your phone number: you switch back to the phone check by verifying with your phone instead of an app code (below). That makes the registered phone number the thing to protect. Keep it current on your account, because both the code in step 5 and that fallback go to it.
If Bithumb rejects your code
Bithumb's help doesn't cover rejected codes. The most common cause is the iPhone's clock: open Settings > General > Date & Time and turn on Set Automatically. Novaz warns you when the clock is 15 seconds or more off. Also check that you're typing the Novaz code into Google OTP 인증번호, not the code Bithumb sent by message into the other field. More causes are in Authenticator code not working?
New phone, lost phone, or turning it off
Bithumb uses the same route for all three. Its article on removing Google OTP is written for people who changed phones or deleted the app and are having trouble signing in (Bithumb):
- In the Security Center, select 사용하기 (Use) next to 알림톡(SMS) / ARS 인증.
- Bithumb asks for a Google OTP 인증번호. If you no longer have the app, select 휴대폰 인증으로 진행하시겠어요? (Continue with phone verification?) and verify with your phone instead.
- Select 확인. Google OTP is now off and the phone check is back.
On a new iPhone, then turn Google OTP on again and scan the new barcode. If you have a Novaz iCloud backup or backup file, you can restore Bithumb on the new iPhone instead and skip these steps. See How to transfer your authenticator app to a new iPhone.
If you also changed your phone number, Bithumb's sign-in screen has 다른 인증수단으로 로그인 (Sign in with another method), which lets you verify your identity with your new phone through Korean mobile carrier verification. Bithumb then updates the number on the account (Bithumb). When that isn't possible either, Bithumb's route is heavy: you open a new account and email help@bithumbcorp.com to have your assets moved, with a handwritten consent form and a copy of your ID (Bithumb). Bithumb doesn't say how long that takes. Its customer center number is 1661-5566.
More general advice is in Lost the phone with your authenticator app?
Official Bithumb help
All articles are in Korean.
