Two-factor authentication or 2FA is an advanced and strong security solution to keep our login-protected system, application, and data secured and protected from intrusion and data breaches. With the soaring incidents of cyber-attacks and data breaches, two-factor authentication has become imperative for each different organization. Let’s gain a brief understanding of 2FA, before exploring the different viable two-factor authentication methods.
What is Two-factor Authentication?
Two-factor authentication solution is used to deliver an additional layer of authentication or security check over password-based authentication. This of token-based authorization is added to existing user-credential (password) based authentication layer so that password-based authentication is followed by token-based user-authentication.
An authorized user having security tokens will easily pass the two-factor authentication. While a malicious user, even on knowing the user-credentials, will find it impossible to authenticate the login without the security tokens. You can read more about the 2FA in our related blog two-factor authentication for web apps.
With the brief & a clear understanding of 2FA, we can now go ahead with the two-factor authentication methods.
What are the different authentication methods to perform user-authentication in 2FA?
Two-factor authentication solution is devised on the principle of “something that user knows” and “something that user has”, where the combination of both the elements is used to verify and validate the login-authenticity.
Something that user knows i.e. username and password (user credentials), is a constant element at any given time. This constant element can’t get replaced with some other element. Password (user-credential) is used for the primary authentication check for the login. On successfully passing the password-based authentication, the user is directed to second-factor authentication check.
Something that user has represents the dynamic element i.e. use of multiple and different security tokens for authentication. Here, we have used the term ‘dynamic’ as a user may opt any of the authentication modes for each different login attempt.
Now, let’s explore some viable authentication options that can be used in second-factor authentication check.
- Software Token
Soft tokens or software tokens are unique & ephemeral security codes that can be generated on your smartphones. A user may choose the software token option during second-factor authentication check and can receive security code on their phones to authenticate their login.
- Hardware Token
Unlike software tokens, hardware tokens involve the use of hardware or plug-in devices that are specifically built for generating, receiving, or delivering security code during 2FA check. Seamoon device and YUBI key are examples of some popular and widely used hardware tokens.
- PUSH Notification
PUSH is a web-generated request which is received at an authorized user’s registered number and mobile device. PUSH notification asks the authorized user to approve genuine and valid login authentication request or to decline authentication that is identified as malicious.
OTP or one-time password received via SMS on mobile devices is also a viable but less preferred option for authenticating user-identity during second-factor authentication check.
Interactive Voice Response System or IVRS is an automated voice call meant for receiving or feeding the security code for authentication.
Like SMS, OTP can also be received on registered email IDs of a user.
- Bypass code
Bypass code or recovery code is the last resort for users. In the event of non-availability of software or hardware tokens or any of the above-said options, bypass code can be used for authentication. Bypass code is a recovery code provided by the 2FA solution. This code is kept by the user to overcome the failure of other available authentication modes (if any).
Lastly, it is pertinent to state that the above-defined options are just some of the 2FA authentication methods. 2FA solution providers are consistently trying to improve & enhance user-experience with the addition of more useful, easy and convenient options for authentication. Thus, in near future, 2FA users may find themselves armed with some more viable and handy two-factor authentication options.