Two Factor Authentication (2FA)
Two-factor authentication (2FA), sometimes referred to as two-step verification or dual-factor authentication, is a security process in which users provide two different authentication factor to verify themselves. This process is done to better protect both the user’s credentials and the resources the user can access. Two-factor authentication provides a higher level of security than authentication methods that depend on single-factor authentication (SFA), in which the user provides only one factor — typically, a password or passcode. Two-factor authentication methods rely on a user providing a password, as well as a second factor, usually either a security token or a biometric factor, such as a fingerprint or facial scan.
Two-factor authentication adds an additional layer of security to the authentication process by making it harder for attackers to gain access to a person’s devices or online accounts because knowing the victim’s password alone is not enough to pass the authentication check. Two-factor authentication has long been used to control access to sensitive systems and data, and online service providers are increasingly using 2FA to protect their users’ credentials from being used by hackers who have stolen a password database or used phishing campaigns to obtain user passwords.
Categories of 2FA
2FA is an extra layer of security used to make sure that people trying to gain access to an online account are who they say they are. First, a user will enter their username and a password. Then, instead of immediately gaining access, they will be required to provide another piece of information. This second factor could come from one of the following categories:
- Something you know: This could be a personal identification number (PIN), a password, answers to “secret questions” or a specific keystroke pattern.
- Something you have: Typically, a user would have something in their possession, like a credit card, a smartphone, or a small hardware token.
- Something you are: This category is a little more advanced, and might include biometric pattern of a fingerprint, an iris scan, or a voice print.
- A location factor: This usually denoted by the location from which an authentication attempt is being made, can be enforced by limiting authentication attempts to specific devices in a particular location or, more commonly, by tracking the geographic source of an authentication attempt based on the source Internet Protocol (IP) address or some other geolocation information, such as Global Positioning System (GPS) data, derived from the user’s mobile phone or other device.
- A time factor: This restricts user authentication to a specific time window in which logging on is permitted and restricts access to the system outside of that window.
With 2FA, a potential compromise of just one of these factors won’t unlock the account. So, even if your password is stolen or your phone is lost, the chances of someone else having your second-factor information is highly unlikely. Looking at it from another angle, if a consumer uses 2FA correctly, websites and apps can be more confident of the user’s identity, and unlock the account.
It should be noted that the vast majority of two-factor authentication methods rely on the first three authentication factors, though systems requiring greater security may use them to implement multifactor authentication (MFA), which can rely on two or more independent credentials for more secure authentication
Common Types of 2FA
If a site you use only requires a password to get in and doesn’t offer 2FA, there’s a good chance that it will be eventually be hacked. That doesn’t mean that all 2FA is the same. Several types of two factor authentications are in use today; some may be stronger or more complex than others, but all offer better protection than passwords alone. Let’s look at the most common forms of 2FA.
Hardware Tokens for 2FA
Probably the oldest form of 2FA, hardware tokens are small, like a key fob, and produce a new numeric code every 30-seconds. When a user tries to access an account, they glance at the device and enter the displayed 2FA code back into the site or app. Other versions of hardware tokens automatically transfer the 2FA code when plugged into a computer’s USB port.
They’ve got several downsides, however. For businesses, distributing these units is costly. And users find their size makes them easy to lose or misplace. Most importantly, they are not entirely safe from being hacked.
SMS Text-Message and Voice-based 2FA
SMS based 2FA interacts directly with a user’s phone. After receiving a username and password, the site sends the user a unique one-time passcode (OTP) via text message. Like the hardware token process, a user must then enter the OTP back into the application before getting access. Similarly, voice-based 2FA automatically dials a user and verbally delivers the 2FA code. While not common, it’s still used in countries where smartphones are expensive, or where cell service is poor.
For a low-risk online activity, authentication by text or voice may be all you need. But for websites that store your personal information — like utility companies, banks, or email accounts this level of 2FA may not be secure enough. In fact, SMS is considered to be the least secure way to authenticate users. Because of this, many companies are upgrading their security by moving beyond SMS based 2FA
Software Tokens for 2FA
The most popular form of two-factor authentication (and a preferred alternative to SMS and voice) uses a software-generated time-based, one-time passcode (also called TOPT, or “soft-token”).
First, a user must download and install a free 2FA app on their smartphone or desktop. They can then use the app with any site that supports this type of authentication. At sign-in, the user first enters a username and password, and then, when prompted, they enter the code shown on the app. Like hardware tokens, the soft-token is typically valid for less than a minute. And because the code is generated and displayed on the same device, soft-tokens remove the chance of hacker interception. That’s a big concern with SMS or voice delivery methods.
Best of all, since app based 2FA are available for mobile, wearables, or desktop platforms — and even work offline — user authentication is possible just about everywhere.
Push Notification for 2FA
Rather than relying on the receipt and entry of a 2FA token, websites and apps can now send the user a push notification that an authentication attempt is taking place. The device owner simply views the details and can approve or deny access with a single touch. It’s passwordless authentication with no codes to enter, and no additional interaction required.
By having a direct and secure connection between the retailer, the 2FA service, and the device, push notification eliminates any opportunity for phishing, man-in-the-middle attacks, or unauthorized access. But it only works with an internet-connected device, one that’s able to install apps to. Also, in areas where smartphone penetration is low, or where the internet is unreliable, SMS-based 2FA may be a preferred fall-back. But where it is an option, push notifications provide a secure form of security.
Other Forms of Two-Factor Authentication
Biometric 2FA, authentication that treats the user as the token, is just around the corner. Recent innovations include verifying a person’s identity via fingerprints, retina patterns, and facial recognition. Ambient noise, pulse, typing patterns, and vocal prints are also being explored. It’s only a matter of time before one of these 2FA methods takes off…and for biometric hackers to figure out how to exploit them.
Rather than building 2FA themselves, many businesses find that it’s smarter and more cost-effective to partner with an expert. Chibex Technologies offers a comprehensive suite of developer friendly authentication API’s and an SDK that can turn any app into self-branded authenticator.
