Today, cybersecurity is no longer an afterthought in businesses because scammers and hackers are finding their way into systems. That’s where SMS authentication comes in to help with two-factor authentication via text message. Two-factor authentication is a precaution for protecting user accounts and data.

Thanks to the increased use of mobile phones, SMS authentication is the most common secondary authentication approach for verifying users. To be in a position to use two-factor authentication, you must provide two pieces of information or evidence before you can log in to online accounts or apps. In this post, you will learn about SMS authentication and why you might want to use it.

Definition of SMS Authentication

SMS authentication refers to any form of “multi-factor authentication” (MFA) or “two-factor authentication” (2FA). In any 2FA authentication, often SMS authentication functions as the second verifier of a user before granting them access to the platform. 

In 2FA, the SMS-based approach sends a “one-time password” (OTP) to a mobile phone number. This allows you to verify your identity using a code you receive via SMS message. It is one of the good first steps when you want better security.

How Does SMS Authentication Work?

SMS messages provide a simple way of authenticating users. When accessing platforms that use SMS authentication, they will send text messages with authentication codes to you before granting you access. SMS authentication is a possession-based approach that will verify your identity depending on what you own.

In this form of MFA, the system authenticates a user via something that they only possess; in this case, a mobile phone number. So, whenever you try to log in to a system, you first need to provide your login credentials (i.e., username and password).

After the system successfully authenticates your login credentials, the server will then require two-factor authentication. This way, the system confirms that you are who you say you are. To prove this, you will receive authentication codes on your registered mobile number. Next, you have to provide the authentication code to access the application or system. The system will verify the code before giving you access.

Most MFA/2FA support SMS authentication. A good example is Textback’s support for two-factor authentication via its smart enterprise SMS solutions. Using SMS authentication adds an extra layer of security that helps keep bad actors away.

SMS Authentication Security

In practice, experts consider SMS authentication to be a poor avenue for identifying users since the SMS system is hugely insecure. The design of this system was done long ago when cybersecurity was not a factor at all. Usually, the SMS infrastructure is authentication-free and sends and retains data in plain text. This leaves SMS susceptible to eavesdropping. What’s more, SMS relies on mobile numbers that are generally unsafe and are easy to spoof, port, or steal. These are some of the reasons experts cite when they advise against reliance on text messages for authentication.

Advantages and Disadvantages of SMS Authentication

Although experts recommend moving away from using phone numbers to authenticate users, there are various reasons why many organizations and people continue to embrace it. For instance, user familiarity with how SMS authentication works is making many businesses retain text messages as one of their authentication methods. In other words, sending SMS authentication codes seems to be the path of least resistance to MFA compliance. That said, experts warn against the use of text messages to authenticate users. We’ve listed the advantages and disadvantages of SMS authentication. 

Advantages of SMS Authentication

There are several advantages to using text messages to authenticate users. Here are some of them:

More Secure

Passwords tend to be weak since users often forget them or recycle one password across several accounts. Worse still, the password may have been stolen because of poor storage practices like writing your password on a sticky note. This can make it easy for a bad actor to gain access to your account. With SMS authentication, you can decrease your dependence on passwords, which will make it a lot harder for third-party participants to compromise your login credentials to hack your accounts.


The obvious reason most users recycle passwords is the sheer number of online accounts they have. Fortunately, SMS authentication eliminates the hassle since it sends a unique code directly to you, as the user. This allows you to verify your identity before getting access to the system.

No Need to Update Operating System

Unlike authenticator apps that may require you to update your phone’s operating system, SMS does not place such demands. You can even use old phones, including feature phones, to receive authentication text messages. 

Disadvantages of SMS Authentication

Even though the use of SMS is convenient and easy to implement, experts raise concerns about its security. Below are some of the drawbacks of using SMS to authenticate users. 

SIM Swapping

Although the thought of getting an authentication factor via text message on a personal phone number sounds safe, it may surprise you that hackers can find ways of intercepting text messages. For instance, they can contact your phone company using your personal details and request that your number be swapped to a different phone. This way, the hacker gets access to any SMS authentication codes sent to your phone number.

No Encryption in Text Messages

Text messages do not have end-to-end encryption. As a result, both cellular providers and governments can view the content of your text messages. As well, the text message remains in the system for days, but the metadata stays much longer. As well, hackers can intercept text messages. Mobile phones connect via a signaling protocol that was established long before cybercrime. In the past, the break in the signaling system has allowed hackers to access bank verification codes. As such, it is a less secure method of authentication or communication.

SMS Spoof

Not long ago, phishing was popular on laptops and computers. However, the advent of smartphones with internet access opens them to similar exploits. Criminals can use spoof messages to pretend to be trustworthy organizations and then send you a link that directs you to a site that requests crucial details such as authentication codes and passwords. A criminal can use text messages to trick you into opening a link to confirm its authenticity. Sometimes, this may be all they want to hack your mobile device.


  • More secure
  • Convenient
  • No need to update the operating system


  • SIM swapping
  • No encryption in text messages
  • SMS spoof

How to Use Authentication SMS

The process of using SMS for two-factor authentication is easy and straightforward. Here are the simple steps of how you can set up authentication SMS. 

  • Step 1: Log in to the system using your login credentials. 
  • Step 2: Next, set up your phone number in the system if it supports verification through SMS during login. 
  • Step 3: Log out of the system to try if the 2FA works. 
  • Step 4: Sign in to the system using your credentials. After verifying the credentials, the system will carry out the 2FA via SMS.
  • Step 5: Once you provide the code sent to your phone number, the system will authenticate it before giving you access. 

Two-Factor Authentication (2FA) and Multi-Factor Authentication (MFA)

Both 2FA and MFA are important components in the cybersecurity ecosystem. The introduction of cloud applications is making MFA necessary as businesses move their platforms to the cloud. Companies are putting in place additional security measures to make sure third-party users do not access their systems.

Although sometimes MFA and 2FA are considered synonyms, the truth is the two are not the same. There are differences between multi-factor authentication and two-factor authentication. That said, both of these are forms of authentication.

Differences Between 2FA and MFA

The main difference between MFA and 2FA is that 2FA demands two explicit authentication factors, while MFA requires a minimum of two authentication methods. One of the most common questions in authentication centers on whether MFA is more secure compared to 2FA. Well, the answer is that it depends.

For instance, each MFA combines 2FA, which makes the authentication as secure as the method used. In other words, if you use three forms of authentication like PIN, OTP, and fingerprint, you will be better off compared to using one password. In this case, MFA is stronger than 2FA, which combines Face ID and OTP.

That said, in some instances, 2FA is stronger than MFA. A good example is when a system demands authentication via push notification and fingerprint, which are some of the most secure verification methods available today. In such a case, the previous example of 3 factor MFA falls short. This goes to show that MFA is only as secure as the method of authentication used.

When it comes to authentication, three authentication factors intertwine in MFA and 2FA. Both MFA and 2FA combine various authentication factors. To provide you with context about authentication factors, below is a quick look at each of these factors.

Knowledge: Secret Login Details of the User

The knowledge authentication factor is the most popular and usually relies on a password or PIN. This form of authentication is common in single-factor authentication. It also forms part of the MFA and 2FA. As one of the initial types of authentication, passwords in the current cybersecurity setting are turning out to be a weak link. Today, even the most experienced hackers are easily cracking passwords.

Possession: Something You Own as a User

This authentication factor refers to owning something such as a smart card or a smartphone. Suppose a system requires you to authenticate your purchase online using a one-time password you receive on your smartphone. This authentication approach lets you use what you possess, such as a mobile phone, to verify your identity. Today, the use of OTP is a popular approach for verifying payments because of its availability through mobile phones.

Inherence: Something You Are as the User

This authentication factor depends on biometric authentication using the unique traits of the user. Usually, biometric authentication includes face and fingerprint recognition together with location. Because biometrics is difficult to spoof, this form of authentication is the most secure. When it comes to multi-factor authentication and two-factor authentication, biometrics are the favorites.

Why Single-Factor Authentication Is Not Enough

With single-factor authentication, you only need to provide one security factor. Often, you get to access business and personal accounts using a password. However, some platforms will prompt you to submit a second authentication factor. The reason is that the platforms understand the security risks if you are only using a password to access your account.

Today, cybercriminals are employing various password-cracking techniques like phishing, brute force scripts, and keylogging that have a high success rate. Therefore, if you are only using passwords as your defense mechanism, then it is high time you consider MFA and 2FA solutions that suit your needs.

There is even talk of eliminating passwords altogether. As it stands, it seems to be more than just talk since there are steps in that direction. For instance, Apple is slowly transitioning the use of passwords by introducing passkeys, which are digital keys generated through Face ID or touch. Therefore, as businesses and individuals transition from passwords, ensure you are up to date by putting in place an MFA or 2FA that suits your business.

How Can Textback Help You to Use Secure SMS Authentication with 2FA and MFA?

Texback offers a comprehensive MFA and 2FA solution that will protect cloud-based systems, remote desktops, and VPNs through various authentication techniques. The platform allows you to test its service for free, be it for business or personal use. Although using text messages for authentication is not entirely safe, it is a convenient alternative to email or complements email-based authentication.

To make it convenient, Textback does not require you to install an application on your mobile phone or device. Rather, you can access the platform through a web browser. When you use SMS as part of an elaborate authentication and verification solution, you get a rather positive outlook. For example, you can combine context-based solutions like phone location to establish suspicious activity, such as the use of phone numbers in locations popular with fraud.

Better still, you can program the authentication code to expire quickly – like in 2 minutes after a user receives it. Also, the platform relies on high-quality routes supported by reliable operators. This makes it harder for hackers to intercept one-time passwords. Textback provides businesses with a strong 2FA option that integrates seamlessly across multiple platforms to support enterprise-level access.

SMS authentication makes it hard for a bad actor to access an account via compromised login details. Even though no single security measure is foolproof, putting in place an SMS 2FA offers an organization with an additional layer of protection. Therefore, using Textback, you can implement 2FA to allow users to include it for security to protect their accounts.