Two-factor authentication (2FA) is significantly more secure than using just a password. Requiring two forms of authenticating evidence simply makes it more difficult to crack your security system. However, two-factor authentication isn’t hack proof.
So just how secure is two-factor authentication? Is it worth the effort to implement 2FA? Should everyone adopt multi factor authentication? Let’s start with looking at how secure two-factor authentication is.
How Secure is Two-Factor Authentication?
Instances where two-factor authentication has been defeated prompt people to wonder, how secure is two-factor authentication? Two-factor authentication is very secure. No, it’s not perfect. Two-factor authentication can be defeated. But it’s very challenging to bypass good two-factor authentication. Only very skilled and dedicated criminals can defeat 2FA.
So, if you’re using two-factor authentication, you don’t have to run out and pick up a multi-factor authentication solution like an app or buy physical authentication keys. 2FA is quite secure.
If you’d like to beef up your cybersecurity, revising your password security policies will get you much more bang for your buck. Strengthening your passwords is much easier than adding another layer of authentication. And it strengthens your two-factor authentication.
How Two-Factor Improves Security
Imagine a door lock that required two keys to open. Now imagine that one of those keys could only unlock that door lock once and you’d have to have a new key made each time you unlocked the door. That’s similar to how two-factor authentication works.
Most 2FA systems require a username and password—which is one form of authentication—and a single-use code that the user enters after they’ve entered their username and password. That single-use code is the second form of authentication. The three types of authentication are:
- Something you know - Like a username and password combination
- Something you have - This is something in your position, like a device
- Something you are - A biometric, like a fingerprint
Requiring two pieces of authenticating evidence (otherwise known as credentials) makes it much harder to breach your security because a criminal must gain access to both the username and password and the single-use code. If your two-factor authentication is properly implemented, gaining access to both credentials means breaching two devices or systems.
Since passwords get stolen and leaked all the time, having a second layer of security will prevent a lot of breaches and make your security posture much better. But, unfortunately, even a double authentication system isn’t perfectly secure.
Problems Facing 2FA
The overarching theme of the 2FA problems is that two-factor authentication has been around for a long time. So bad actors have had plenty of time to figure out ways to beat two-factor authentication. These methods are related to two weaknesses in 2FA.
First, a two-factor authentication system that uses a password as one form of authentication is using one relatively weak credential. Passwords are frequently exposed in data breaches and leaks. That’s why it’s wise to change your passwords regularly.
The second 2FA problem is that the single-use authentication code must be transmitted to the security system. It’s possible for a bad actor to intercept and read the code as it’s being transmitted to the user’s device.
But remember that a criminal needs to defeat both aspects of 2FA. A bad actor must first gain access to a user’s password. Then the criminal must find out what device is used for 2FA and compromise that device, which has its own safeguards. That’s why two-factor authentication is so much more secure than single-factor authentication.
The bottom line is that while two-factor authentication isn’t unbreakable, it’s far more secure than single-factor authentication and more cost efficient than more complex authentication methods.
Can Two-Factor Authentication be Hacked?
It’s a very strong security protocol. But two-factor authentication can be hacked. A compromised password paired with a compromised device can cause 2FA to fail. But, if you’re careful about your internet activity and use a secure SMS service, the chances of 2FA being hacked are very slim.
The two most common methods of hacking two-factor authentication are man-in-the-middle attacks and SIM swapping.
There are a lot of details involved with these two methods. But the short version is that a criminal must either breach your SMS carrier’s network or convince a cell phone carrier to transfer the victim’s phone number to a new SIM card.
If you have good password security and a quality SMS carrier, it’s very difficult for criminals to defeat your two-factor authentication. In fact, it might be impossible for most criminals, as they won’t have the necessary skills to bypass 2FA and will move on to easier targets.
Best Practices for 2FA
Even though two-factor authentication is quite secure, there are a few best practices for 2FA that you should follow to maximize your cybersecurity posture.
Implement strong password policies. Use long passphrases with at least one non-dictionary word and change your passwords every 30 to 90 days.
The password is the weakest link in your two-factor authentication system. Good password policies will help mitigate this weakness.
Use time limited 2FA codes. Single-use codes are good. But codes that expire after a few minutes are even better. That way, unused codes can’t be picked up and used later.
Also, if the code expires before a criminal is able to compromise the user’s device and read the code, their attack fails. Codes that expire are the most secure.
Partner with an SMS carrier that prioritizes security. One of the challenges of two-factor authentication is that you have to rely on a third party network to send 2FA codes. If your SMS carrier’s network is compromised, your two-factor authentication is potentially compromised.
The best SMS carriers for 2FA are those that operate a private network, with end-to-end encryption.
A private network minimizes the attack surface. So it’s difficult for cybercriminals to access your carrier’s network at all, let alone breach the network.
Then, end-to-end encryption protects your 2FA codes if the network is compromised. The codes must be decrypted before a bad actor can use them. With time limited codes, that makes it nearly impossible to crack your two-factor authentication.
Choosing a quality SMS two-factor authentication provider minimizes the risk of having your security breached because your carrier’s network gets compromised.
Ultimately, two-factor authentication is secure. And with the right policies and best practices, it can be nearly unbreakable.
FAQs
2FA can be vulnerable to several attacks from hackers because a user can accidentally approve access to a request issued by a hacker without acknowledging it. This is because the user may not receive push notifications by the app notifying them of what is being approved.
How much safer is two-factor authentication? ›
Two factors are better than one
Using two-factor authentication is like using two locks on your door — and is much more secure. Even if a hacker knows your username and password, they can't log in to your account without the second credential or authentication factor.
Can hackers beat 2 factor authentication? ›
Use authenticator apps
Most 2FA methods involve sending temporary codes via SMS or emails, but these can be easily intercepted by hackers through account takeover, SIM swapping, and/or MitM attacks.
Is 2FA strong authentication? ›
But it's the combination of both a secure password and a secondary credential via 2FA that makes it so difficult for cyber criminals to breach. Both a strong password and two‑factor authentication are absolutely crucial for securing online identities, explained Laura Kankaala, F‑Secure's Threat Intelligence Lead.
How safe is multi-factor authentication? ›
Multi-factor authentication (MFA) is known for being the gold standard in security access. It helps protect sensitive accounts and data by requiring an extra layer of authentication such as a password, PIN, or One-Time Password (OTP).
What are the disadvantages of 2FA? ›
Dependence on a second factor: E.g., if a smartphone is misplaced, the user will be blocked from their account. Flexibility: IT leads can choose which second factors to deploy. Resistance to change: If users are unfamiliar with 2FA, it could feel intrusive.
Why is 2FA no longer safe? ›
Even if the user doesn't respond to a push login request or doesn't enter a One-Time Password (OTP) when prompted, a hacker still knows they have a working password now; how, because the delay for the denied message takes longer... Most of us know where this is going; the hacker is persistent in their login attempts.
What is better security than two-factor authentication? ›
Multi-Factor Authentication: A Step Beyond
2FA uses two items. Multi-factor authentication uses two or more items for authentication. Using a password and an email address, for instance, is always going to be inherently less secure than using a password, email address, and also a physical device.
Which two-factor authentication method is the safest? ›
Hardware security keys like YubiKey provide the most secure form of two-factor authentication. Unlike SMS or authenticator apps which can be phished, hardware keys offer phishing resistant authentication by requiring physical possession of the key.
What is the strongest form of two-factor authentication? ›
FIDO U2F is the most secure form of 2FA that prevents against password cracking, man-in-the-middle, and phishing attacks. Learn more about FIDO U2F here.
SMS and email OTPs are weaker
Anyone with an email account or a cell phone can use them without downloading yet another app. On-demand OTPs are also popular with threat actors. Hackers can intercept OTPs through weaknesses in SMS or email delivery methods.
What is the weakest authentication? ›
Passwords are considered to be the weakest form of the authentication mechanism because these password strings can be exposed easily by a dictionary attack. In this automated framework, potential passwords are guessed and matched by taking arbitrary words.
What is the strongest form of authentication? ›
Physical security key
A physical authentication key is one of the strongest ways to implement multifactor authentication. A private key, stored on a physical device, is used to authenticate a user, such as a USB device that a user plugs into their computer while logging in.
Why is two-step verification bad? ›
2FA can be vulnerable to several attacks from hackers because a user can accidentally approve access to a request issued by a hacker without acknowledging it. This is because the user may not receive push notifications by the app notifying them of what is being approved.
Can hackers get around 2 factor authentication? ›
Two-factor authentication is a powerful security measure, but it is not impervious to hacking attempts. Hackers have devised various techniques to bypass 2FA and gain unauthorized access to user accounts. Let's explore some of the common methods used by hackers and the measures you can take to mitigate these risks.
What is the safest authentication? ›
Our top 5 authentication methods
- Biometric Authentication Methods. Biometric authentication relies on the unique biological traits of a user in order to verify their identity. ...
- QR Code. ...
- SMS OTP. ...
- Push Notification Authentication Method. ...
- Behavioral Authentication Method.
The most secure Multi-Factor Authentication method is a phishing-resistant type of MFA, which means that attackers cannot intercept or dupe users into providing account access. Phishing-resistant types of MFA include FIDO2 and WebAuthn standard, hardware-based security keys.
Why not to use two-factor authentication? ›
2FA, and multi-factor authentication as a whole, is a reliable and effective system for blocking unauthorized access. It still, however, has some downsides. These include: Increased login time – Users must go through an extra step to login into an application, adding time to the login process.
What are the criticism of two-factor authentication? ›
In addition, 2FA really doesn't provide identity authentication. Instead, it authenticates devices under the assumption that the owner of a particular device will be the only individual using it, which can certainly be incorrect.
Is 2FA really secure? ›
As one of the most common methods of verifying identity, 2FA is often touted as a secure authentication solution (despite lukewarm adoption), but it leaves open many opportunities for hackers to infiltrate your most mission-critical applications and systems, putting your login credentials at risk.
MFA protects businesses by adding a layer of security that can block 99.9% of attacks stemming from compromised accounts. For example, a phishing attack may obtain a user's credentials, but be unable to provide the fingerprint or security question response required for authentication.
Is two-factor authorization secure? ›
While 2FA does improve security, it is not foolproof. Two-factor authentication goes a step further in verifying identity from the user simply entering a PIN or CVV number from their credit card. However, hackers who acquire the authentication factors can still gain unauthorized access to accounts.
What is the safest authentication type? ›
More Secure: Biometrics. Biometric authentication methods rely on something you are. That makes them hard to steal, difficult to misplace or share, and impossible to forget. Users are comfortable with them, and they increasingly come built-in on our devices.
Does two-factor authentication prevent identity theft? ›
Two-Factor Authentication (2FA) is a critical security measure that adds an extra layer of protection to online accounts. By requiring users to provide two forms of identification, such as a password and a unique code sent to their mobile device, 2FA significantly reduces the risk of unauthorized access.
