Migrating OTP Services from Google Authenticator to Other Providers

Migrating OTP Services from Google Authenticator to Other Providers

One-time password (OTP) authentication is widely used to enhance security in online services. If you’re looking to migrate your OTP service from Google Authenticator to another provider, this guide will walk you through the process step by step. Additionally, we’ll cover the basics of OTP authentication with a simple graphical explanation.

---

Understanding OTP Authentication

OTP (One-Time Password) is a time-based or counter-based authentication method that generates a unique code for each login attempt. The authentication process typically follows these steps:

1. Secret Key Generation: The service provider generates a secret key unique to the user.
2. QR Code Encoding: The secret key is encoded into a QR code for easy scanning.
3. User Registration: The user scans the QR code using an authentication app (e.g., Google Authenticator, Authy, or Microsoft Authenticator).
4. Code Generation: The app generates time-based OTPs using the secret key.
5. Verification: The user enters the OTP during login, and the service verifies its validity.

Why Does an Authenticator App Work Without Internet?

Authenticator apps use a Time-based One-Time Password (TOTP) algorithm, which relies on the shared secret key and the current time rather than requiring an internet connection. The OTP is generated using the following formula:

OTP = HMAC-SHA1(secret_key, current_time_interval)

• Both the authenticator app and the service provider use the same secret key.
• The current time is divided into fixed intervals (typically 30 seconds).
• The algorithm generates an OTP based on the secret key and the current time interval.
• Since both the app and the service provider compute the OTP using the same inputs, the code can be verified without needing network communication.

---

Step-by-Step Migration Process

1. Install and Download OTPAuth

First, install the OTPAuth tool, which helps extract QR codes and transfer OTPs. On macOS, you may need to remove quarantine attributes before running it:

sudo xattr -d com.apple.quarantine ./otpauth

2. Export OTP Secrets from Google Authenticator

Google Authenticator allows exporting OTP configurations using a QR code. Follow these steps:

• Open Google Authenticator.
• Tap the menu and select Export Accounts.
• Scan the QR code or extract it for further processing.

3. Extract OTP Secret from QR Code

Use a QR code scanner or the otpauth tool to decode the QR code and extract the OTP URL:

./otpauth -d /path/to/qr_code.png

The extracted OTP URL will be in the format:

otpauth://totp/ServiceName:Username?secret=YOUR_SECRET_KEY&issuer=ServiceName

4. Import OTPs into Another Authentication App

Once you have the OTP URL, you can manually add it to your new authentication app:

• Open your preferred authentication app (e.g., Authy, Aegis, 1Password, or Microsoft Authenticator).
• Add a new account manually.
• Enter the extracted secret key or scan a newly generated QR code.

5. Verify the OTPs Work

Test the generated OTPs by logging into the service and ensuring the codes match.

---

Simple Diagram of OTP Workflow

[Service Provider] ---> [Generates Secret Key] ---> [QR Code]
[User] ---> [Scans QR Code] ---> [Authenticator App]
[Authenticator App] ---> [Generates OTP] ---> [User Inputs OTP]
[Service] ---> [Verifies OTP] ---> [Access Granted]

This diagram illustrates how OTP authentication works and why migrating OTPs requires securely transferring the secret key.

---

Final Thoughts

Migrating OTP services from Google Authenticator to another provider is a straightforward process if you follow the right steps. By extracting and securely transferring the OTP secret, you can ensure seamless authentication with your new app. Always remember to back up your OTP secrets to avoid losing access to your accounts.

By following this guide, you can take control of your OTP authentication and choose the provider that best suits your needs.