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SMS Authentication — Can it Really Protect Your Business?

Protecting your business with two-factor/ multi-factor authentication is a great way to keep unauthorized users away from your confidential data. But are SMS secure enough for this purpose? Are there any other security flaws involved in using SMS for authentication? Let’s find out.

An Overview

With growing numbers of websites and consumers on those websites, authenticating each one of them becomes an arduous task. Also, it becomes an important aspect to protect and secure the consumer's data available on your application. To protect sensitive consumer data, two-factor authentication became a mandatory requirement in today's digital world.

Two-factor authentication can be done via multiple channels. One is by using google authenticator codes, and the other is sending OTP on the consumer's email. But the easiest and convenient way is to do it via SMS.

SMS stands for Short Messaging Service, which you guessed right. The text messages that we get on our mobile phones. This SMS holds an One Time Password (OTP), used to validate the consumer login. So basically, it can be used as a backend agent who reaches out to the original consumer and provides him access to any network, system, or web application.

How does SMS Authentication Work?

A short messaging service (SMS) is generally used to carry any information to the end-user. It can be information like promotional messages, notifications, or personal texts, but they also carry authentication codes (OTPs).

Using SMS authentication is quite simple and easy to understand. When a consumer tries to log in to a website, system, or network, he provides the login credentials. On successfully authenticating the login credentials, the server now does a two-factor authentication. It ensures that the consumer trying to log in is who he says he is. To authenticate the user, a text SMS and an OTP are sent to the consumer's registered mobile number. When that OTP is entered, the consumer gets authenticated, and then only they can access the contents of the system/application.

SMS authentication is based on one of the three types of multifactor authentication, i.e., Possession based authentication. In this type of MFA, the consumer is authenticated via something that only he can possess, which is the mobile handset.

Merits and Demerits of Using SMS Authentication

Everything in this world holds both the concepts of merits and demerits, and so does SMS authentication. Let's first discuss the merits that it has.

  1. Additional Layer of security: Two-factor authentication is now widely used to protect consumers' account data. SMS authentication provides an extra layer of protection that too without any complexity. At least it is far better than having no additional security check.
  2. Ease of usage: It is the human behaviour that we always look for an easy way to get our work done. Now imagine having a complex two factor authentication setup. Users will end up frustrated doing complex authentications. Here SMS authentication rises as an easy and secure option.
  3. Ease of usage: It is human behavior that we always look for an easy way to get our work done. Now imagine having a complex two-factor authentication setup. Users will end up frustrated doing complex authentications. Here SMS authentication rises as an easy and secure option.
  4. Low Cost: Sending SMS to consumers includes minor charges, which helps a lot for the organization with a large consumer base.

Even after being so convenient and easy to operate, there are some demerits also. These demerits are capable enough to make the organizations think that it is enough to protect the business. Let's discuss them one by one:

  1. SIM Highjacking or Device theft: It looks effortless to send the verification code on a mobile number and authenticate consumers based on that. But the Option of SMS authentication can be harmful if the SIM/device got lost or stolen by someone. As in this case, SIMs can easily be used on other mobile phones, and they will still receive the validation code.
  2. Hacking: Earlier, it was complicated to intercept GSM-based SMS, but as the technologies are evolving, hackers have also got more power in their hands. The regular text which is sent and received over mobile phones can easily be intercepted today.
  3. Social Engineering Attacks: Compared to earlier days, more devices are now connected to the internet today. Today, a simple phishing link via a text msg or any advertisement will do the job. If a consumer clicks on the link by mistake or falls into any such trap, all his data will be gained by hackers, including SMS.


Should Businesses Use SMS Authentication?

With all the demerit points discussed above and keeping all the security issues in mind, businesses might want to reconsider their authentication methodology. It is known very clearly that cybercrimes and hackers are overgrowing, especially after the internet revolution.

Hacking groups and organizations are getting sophisticated daily, and SMS authentication has not evolved with such changes. We are still using a similar old mechanism to send text messages.

Hence, intercepting a text message is easier as compared to earlier days.

So to answer the big question, yes, it is better to have some two-factor authentication in the form of SMS authentication, but businesses should not rely entirely on it. They must think of other possible authentication mechanisms if they are collecting sensitive consumer data.


Dropping the idea of SMS authentication might look easy. Still, it is a bit difficult for some organizations because, as we already mentioned, SMS authentication is a very well-established method and has been used for a long time. The convenience provided in authenticating the end-users is also unparalleled.

But businesses need to find an alternative for this as SMS authentication cannot be heavily relied upon. The key to achieving that is to find any other authentication method which is as easy, convenient, user-friendly, and secure at the same time. Going with the new trends in the technologies, Biometric Authentication is one feasible solution. Well, we will indeed talk about that some other day :)


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Ashish Kumar Yadav

Written by Ashish Kumar Yadav

Technical Support Engineer at LoginRadius. Handles day-to-day customer technical queries regarding integration and implementation of various web technologies. A firm believer of hard work. An active runner and a big fan of nature.

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