How to Use Google Authenticator for 2FA

Google Authenticator is a mobile app developed by Google that generates time-based, one-time passcodes (TOTP) for two-factor authentication (2FA). It adds an extra layer of security to online accounts by requiring your regular password and a temporary 6-digit code generated by the app. This reduces the risk of unauthorized access to your accounts, even if your password is compromised.

This blog will discuss how to use Google Authenticator app for two factor/multi factor authentication, how to set it up, its benefits, and more.

Google Authenticator uses a time-based algorithm to generate a new 6-digit passcode every 30 seconds. These codes are generated based on a shared secret key unique to each service you set up. When you attempt to log into an account, input your regular password and the current 6-digit code from the app.

The secret key (OTP) is provided when setting up 2FA and stored in the app. Both the service and the app use the same key to generate the codes, and as long as the times are synchronized, the codes will match.

Google Authenticator app is easy to set up and use. Here are a few steps to follow:

Install the App:

• Android: Download from Google Play Store.
• iPhone: Download from the Apple App Store.

Enable 2FA on Your Account:

To enable 2FA, log in to the account where you want to enable 2FA (e.g., Google, Facebook, etc.). Now, go to the security settings to find the Two-Factor Authentication (2FA) or Two-Step Verification option. Finally, select the Google Authenticator or TOTP option.

Scan the QR Code:

To add any website/app on Google Authenticator for 2FA, get the QR code of the service. Now, open the Google Authenticator app, tap the + icon, and choose Scan the QR code. Your website/app is successfully added to Google Authenticator.

Verify the Code:

The app will now display a 6-digit code. Enter this code on the website to confirm the setup.

Google Authenticator is generally considered to be a secure and effective tool for two-factor authentication (2FA), but its security depends on how it’s used, configured, and managed. Here’s a breakdown of its security features, potential vulnerabilities, and best practices:

Offline Functionality:

Google Authenticator generates time-based one-time passwords (TOTP), which work entirely offline. This means no data is transmitted between your device and Google’s servers while generating codes, reducing the risk of network-based attacks like man-in-the-middle (MITM) attacks.

Time-Based Codes:

The 6-digit codes are generated based on a shared secret key between your device and the service, and they refresh every 30 seconds. This limits the time window for attackers to use a stolen code.

No Internet Dependency:

Since Google Authenticator doesn't rely on internet access or SMS, it's immune to network vulnerabilities such as SIM-swapping attacks, which can compromise SMS-based 2FA.

Multiple Account Support:

You can add codes for multiple accounts in a single app. However, each account remains isolated within the app and requires a separate setup key for its TOTP generation.

No Cloud Sync (Originally):

Google Authenticator originally lacked cloud synchronization, meaning your 2FA codes were stored locally on the device. This design prevented attackers from accessing your codes through cloud-based vulnerabilities. In 2023, Google introduced syncing via Google Account, which enables users to back up codes to the cloud if they opt in. This feature adds convenience but introduces potential cloud-based risks.

TOTP Algorithm:

Google Authenticator uses the HMAC-based One-Time Password (HOTP) and TOTP algorithms, which are industry-standard methods for generating secure, time-based codes.

These are a few benefits of using Google Authenticator:

1. Increased Security: Even if someone steals your password, they won’t be able to access your account without the 6-digit code.
2. Offline Usage: The app generates codes without needing an internet connection.
3. Resistant to SIM Swapping: SMS-based 2FA is vulnerable to SIM-swapping attacks, but Google Authenticator isn’t since it's tied to your device.
4. Multi-account Support: You can store multiple 2FA codes in one app for different accounts.

How to Use Google Authenticator

Once you have enrolled a service in the Google Authenticator app, you will need an OTP to log in the service. To do that, open Google Authenticator on your phone, find the service name, and input the six digit code before it expires (30 seconds). You can log in once the code is verified.

How to Install and Use Google Authenticator App on Android

1. Visit the Google Play Store and search for Google Authenticator to download the app.
2. Now, tap Install.
3. Open the app and tap the + to add a new account
4. Scan the QR code provided by the service or manually enter the setup key.
5. Open the app whenever you need a 2FA code.
6. Input the code displayed next to the account name when prompted during login.

How to Install and Use Google Authenticator App on iPhone

1. Visit the Apple App Store and search for Google Authenticator.
2. Tap Get to install.
3. Open the app and tap + to add accounts
4. Choose Scan QR code or Enter setup key.
5. Scan the QR code or manually enter the setup key for the account.
6. The codes are displayed alongside your account names, and you can use them when required for 2FA.

How to Keep Your Google Authenticator Codes Synchronized Across All Your Devices

• Google Authenticator now supports account synchronization through your Google account (starting from recent versions). This allows your codes to be backed up and synced across multiple devices.
• To enable synchronization, open the Google Authenticator app and sign in with your Google Account.
• Follow the prompts to sync your accounts.

How to Use Google Authenticator Without a Google Account

You can use Google Authenticator completely offline and without linking it to a Google account. Simply:

• Install the app without signing in.
• Add accounts via QR code or setup keys.
• Your codes will be stored locally on the device and not synced with any cloud account.

How to Transfer Your Google Authenticator Codes

You can transfer your Google Authenticator codes to a new phone by following these steps:

1. Open Google Authenticator on your old phone.
2. Tap the three dots (menu), then choose Transfer accounts.
3. Select Export accounts on the old phone and Import accounts on the new phone.
4. Follow the on-screen instructions and scan the QR code from the old phone to the new phone.

How to Use Authenticator with Multiple Google Accounts

Google Authenticator supports multiple Google accounts. To add more than one account:

1. Open Google Authenticator and tap the + button.
2. Scan the QR Code for each account, and it will be added separately within the app.
3. You'll see multiple entries, each labeled with the account name, allowing you to manage 2FA for multiple accounts from one place.

How to Edit, Organize, Delete, or Recover Google Authenticator Codes

Edit/Organize: Google Authenticator doesn’t natively allow you to rename or rearrange accounts. However, codes are displayed in the order they are added.

Delete Codes:

1. Open Google Authenticator.
2. Tap the three dots menu (top right).
3. Choose Delete account, and select the account you wish to remove.

Recover Codes:

1. Use backup codes (if provided during setup).
2. Use the secret key you saved to add the account to a new device during the initial setup.

Enable Strong Device Security:

Protect your phone with a strong PIN, password, or biometric lock to prevent unauthorized access. Ensure that your phone is encrypted, especially for Android devices, which may require encryption to be turned on in settings.

‍Use Google Authenticator with a Backup Plan:

Save the backup or recovery keys when setting up 2FA for each service. This allows you to recover your 2FA codes if your phone is lost or reset. Alternatively, use the sync feature introduced by Google to keep a cloud backup of your codes, but make sure your Google account is well-protected.

Use Authenticator on a Separate Device:

For highly sensitive accounts, some users prefer to run Google Authenticator on a secondary device, separate from their primary phone. This adds an extra layer of protection since your primary device (used for browsing or logging in) and your 2FA device are separate.

Regularly Update the App:

Keep Google Authenticator updated to ensure you benefit from the latest security features and bug fixes.

Use Google Authenticator Alongside Other Security Measures:

Combine Google Authenticator with other security measures such as strong passwords, password managers, and, where possible, hardware security keys (like YubiKey) for the strongest multi-factor authentication setup.

Google Authenticator is a widely used and secure mobile application that significantly enhances online security through two-factor authentication (2FA). We are sure that this comprehensive guide should help you with everything from setting up Google Authenticator to transferring codes, managing multiple accounts, and ensuring security.