Comparison of MFA Methods: Authenticator App vs. SMS vs. Phone

Overview 

Two-Factor Authentication provides an extra layer of security in addition to your password to ensure your account is secure from unauthorized access.  Depending on your situation and preferences, there may be advantages of using one over the other as your primary, default method. 

Microsoft Authenticator App

This method is known to be more secure than SMS text and phone call methods.

Advantages:

• Availability - can be accessed over mobile data or Wi-Fi connection
• Traveling abroad - only usable method when traveling abroad and you're without your usual mobile/cell phone plan
• Security - It is more difficult for a hacker to gain physical access to your phone and generate a code.
• Flexibility - You are able to generate a code within the app if you're not receiving the push notifications to your phone.
• Smart watch - For some smart watch users, such as Apple watch, you can approve your sign ins directly on your watch.

Disadvantages:

• Need to use a smart phone or tablet
• Requires downloading a free app

SMS Text Codes

This method is known to be less secure compared to the Microsoft Authenticator App.

Advantages:

• Non-smart phone users - If you do not have a smart phone, SMS and phone calls may be your only option to receive verification codes. 
• No app to install - SMS text codes may be convenient in that no app is needed to download on your phone or tablet. It's a straightforward, simplistic method using what you already have installed.

Disadvantages: 

• Less secure - The codes sent via text are likely not encrypted (texting apps may vary), making them less secure than authentication apps.  It is easier for a hacker to gain access through this method. They can hack into your phone carrier, redirect your text messages, or have access to your SIM card where the text messages can be directed to them instead. 
• Traveling abroad - SMS cannot generate a code for you to use. Users will end up having to download the app. 
• Mobile data - Requires mobile data to generate a text message code
• Waiting for a code to generate can take longer if your mobile data connection is weak.

Phone Call

This method is known to be less secure compared to the Microsoft Authenticator App.

Advantages:

• Non-smart phone users - If you do not have a smart phone, SMS and phone calls may be your only option to receive verification codes. 
• No app to install - Phone calls may be convenient without the need of downloading an app to your phone, as it is a simple method of a phone call.

Disadvantages:

• Less secure - The codes sent via phone call are likely not encrypted (phone apps may vary), making them less secure than authentication apps. It is easier for a hacker to gain access through this method. They can hack into your phone carrier, redirect your phone calls, or have access to your SIM card where the calls can be directed to them instead. 
• Traveling abroad - Phone calls abroad cannot generate a code. Users will end up having to download the app. 
• Mobile data - Requires mobile data to generate a phone call.

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