Introduction to 3rd party Authenticator Apps

Introduction

The world of social media today is both exciting and secure, but with the increasing reliance on online platforms, security has become a top priority. A casual scroll through Instagram got me wondering: what security measures are in place to keep our data safe? With stories of data breaches and hacking attempts surfacing every day, I wanted to better understand how Instagram protects its users. I decided to explore the security options available, especially two-factor authentication (2FA), which offers an extra layer of security beyond just a password.

When I navigated to the Security section in Instagram’s settings, I found two 2FA options: Authentication App and SMS/WhatsApp. I’d used SMS-based 2FA before, which sends a code via text, but this time, I was curious to try the authentication app option to understand how it works technically and why it's generally considered more secure than SMS-based methods. Let’s dive into what I discovered and why using an authenticator app might be one of the best ways to secure your crucial applications.

What is an Authenticator App and Why Do We Need It?

In simple terms, an authenticator app is a mobile app that generates a unique code for a specified amount of time (usually 30 seconds), allowing you to complete the login process securely. Even if someone knows your password, they wouldn’t be able to access your account without this extra code, which is dynamic and changes frequently.

Authenticator apps use a secure, algorithm-driven process to generate these one-time passwords (OTP) that align with a unique secret key assigned to your account. This is different from SMS-based 2FA, where codes are sent over cellular networks and can be intercepted or fall prey to SIM-swapping attacks. Examples of popular authenticator apps include Google Authenticator and Microsoft Authenticator, both of which are easy to use, trusted, and widely supported by various platforms.

Step-by-Step Breakdown: How Instagram’s Authentication App 2FA Works

Let’s get into the technical details of how this process works and what happens behind the scenes when you use an authentication app with Instagram.

Step 1: Generating a Secret Key

When you first set up 2FA using an authenticator app in Instagram, Instagram’s backend generates a secret key. This secret key is unique to your account and serves as the basis for generating the time-sensitive OTP codes. Since this key is kept confidential and securely stored, it’s what makes this system so resilient.

Step 2: Generating a QR Code

Next, Instagram presents you with a QR code containing the details of your 2FA setup. The QR code represents a URI (Uniform Resource Identifier) structured in the following format:

otpauth://{type}/{app}:{accountName}?secret={secret}{query}

This URI includes essential details required to set up 2FA on your account:

• {type}: The type of algorithm used, either TOTP (Time-based One-Time Password) or HOTP (HMAC-based One-Time Password). TOTP is by far the most common and secure choice for most apps, including Instagram, as it generates a new code every 30 seconds based on time, while HOTP relies on a counter-based system.
• {app}: The name of the app, in this case, Instagram, which will show up in the authenticator app interface after you scan the code.
• {accountName}: Your account’s username or email address associated with Instagram. This information allows you to identify which account the code is for if you have multiple accounts set up in the app.
• {secret}: The secret key unique to your Instagram account. It is critical for generating the OTP codes and should be kept secure.
• {query}: This part of the URI can include optional parameters, like changing the code’s length (from the default 6 digits to a different value) using &digits=4, which would generate a 4-digit OTP.

Step 3: Installing and Setting Up an Authenticator App

To proceed, download an authenticator app like Google Authenticator or Microsoft Authenticator from your device’s app store. Once installed, log in to your Google or Microsoft account if needed. In the app, select the option to Add an Account and then scan the QR code provided by Instagram.

This QR code contains all the details Instagram generated in the previous steps, like your account’s secret key, which will be securely stored in the app for ongoing OTP generation.

Step 4: How OTP Generation Works in the Authenticator App

After scanning the code, your authenticator app starts to generate a 6-digit code that refreshes every 30 seconds. Here’s a bit more about the mechanics behind this:

• The app generates the OTP using the TOTP algorithm, which combines the secret key and the current timestamp.
• The TOTP algorithm essentially applies a mathematical formula to both inputs (secret key and timestamp) to produce a unique OTP that is only valid for a short period.

Since only you and Instagram know this secret key, the OTP generated is unique to your account and changes continuously, making it highly secure.

Step 5: Verification by Instagram

Once you have the 6-digit code from your authenticator app, enter it into Instagram to complete the 2FA setup. Here’s what happens next:

• Instagram takes the secret key stored on their end, applies the TOTP algorithm, and uses the current timestamp to generate a matching code.
• If the code you entered matches the code Instagram generated, the verification is successful. Instagram then securely stores your secret key in its database to support ongoing OTP generation.

Now, each time you log in and are prompted for a 2FA code, the authenticator app will generate a 6-digit OTP. This unique code must match Instagram’s version, which is derived from the same algorithm and timestamp, ensuring secure verification without any need for SMS.

Step 6: Repeating the Process for Each Login

Every time you log in, the authenticator app generates a new 6-digit code, which Instagram verifies using the secret key and current timestamp. Since the app-based OTP changes every 30 seconds, even if someone manages to see your code, it will be invalid after a short time.

Conclusion

Enabling two-factor authentication using an authenticator app is one of the most effective ways to enhance account security on Instagram. Unlike SMS-based codes, which can be intercepted, authenticator app codes are stored and generated within the app itself, offering a safer and more reliable alternative.