What Is Multi-Factor Authentication (MFA)?
Multi-factor authentication (MFA) uses two or more different types of authentication to verify a user’s identity. It was originally created to make it more difficult for an attacker to gain access to an account if they’ve guessed the user’s password or it has been exposed in a breach.
Today, MFA is ubiquitous, used to secure both corporate and personal accounts. The combination of a password and a one-time password (OTP) sent to a smartphone or generated by an authenticator app is the most common approach to implementing MFA. However, many options exist, often offering stronger security. For example, biometrics are considered the strongest type of authentication factor.
The Importance of MFA
MFA was invented to address the shortcomings of traditional, password-based authentication. In theory, users should have a unique, strong password for each account. In practice, many passwords are easy to guess, making it easy for attackers to compromise important accounts.
MFA helps to make account takeover attacks more difficult by requiring the attacker to compromise multiple layers of authentication. It reduces the effectiveness of password guessing and can decrease a user’s vulnerability to phishing attacks. The resulting improvement in account security is why MFA is required by many security regulations and for high-risk accounts, such as those with banking institutions.
What are MFA Authentication Factors?
MFA gets its name from the fact that it requires a user to provide multiple authentication factors to gain access to their account. These authentication factors come from two or more categories.
Something You Know
Knowledge-based authentication factors include passwords, passphrases, PINs, and security questions. Ideally, these should be unique and randomly generated or be something known only to the legitimate user.
However, users tend to reuse passwords or choose easily memorable ones due to the sheer number of online accounts. This has sparked a trend toward passwordless authentication, which avoids these knowledge-based factors to enhance security and usability.
Something You Have
Possession-based authentication factors validate a user’s identity based on their possession of a particular device, such as a smartphone, laptop, smart card, or hardware token. The most common example of this is an authenticator app that generates OTPs. Another option is digital certificates stored on a device, smart card, or hardware token.
Something You Are
Biometric authentication factors use a user’s unique characteristics to identify them. Common examples include fingerprint, facial, or voice recognition.
While physical characteristics are more commonly used, it’s also possible to use unique behavioral traits for authentication. Some examples include modeling the user’s walking gait, typing patterns, or how they use a smartphone.
Biometrics are the most secure of the three most common types of authentication factors. However, they also face significant privacy and security concerns since they require storing personally identifiable information (PII) and can’t be changed if breached.
Other Authentication Factors
While these three types of authentication factors are the most common choices for implementing MFA, they’re not the only options. An authentication system can use anything unique to a user to identify them. For example, some systems may use “somewhere you are” as a factor, using geolocation or IP addresses as part of the identity verification process.
Common Authentication Mechanisms of MFA
Certain authentication factors are more common than others, especially for online accounts.
Password
Passwords are the most common method people use to prove their identity online. This should involve a long, random password that is unique to a particular account. However, many users select weak passwords, undermining their account security. This is one of the main reasons that MFA was invented and the driver behind passwordless authentication.
One-Time Passwords (OTPs)
OTPs are one-time codes that are used as part of a “something you have” authentication factor. Typically, these codes are generated by an authenticator app or sent to a device via text message (though this is insecure).
Authenticator apps use a couple of different schemes to generate OTPs in sync with an authentication server. In both cases, the app and server synchronize during account creation, often by having the user scan a QR code. From there, time-based OTPs (TOTPs) generate a new OTP at fixed intervals, while HMAC-based OTPs (HOTPs) generate a new code only after a successful authentication.
Push Notifications
Push notifications are another common method of implementing “something you have” authentication using a smartphone or tablet. These systems send a notification to the device, and the user can open the notification and verify that they were the individual who made the login attempt. Push notifications can also be used to deliver an OTP to a device.
Hardware Tokens
Hardware tokens like Yubikeys are another form of “something you have” authentication. These devices may generate OTPs or digital signatures to prove a user’s identity. Since they are standalone devices with built-in anti-tampering defenses, they are considered more secure than authenticator apps and similar systems.
Biometric Scanners
Biometric scanners include various systems for recognizing fingerprints, faces, voices, or other unique features. Biometrics are the most secure form of authentication and have become more common with the growth of smartphones with built-in cameras and fingerprint scanners.
How Does MFA Work?
MFA uses multiple authentication factors to control access to a system. This can be broken up into four main stages:
- User Identification: Identification determines which account the user is attempting to access. This is accomplished via a username or email address.
- Primary Authentication: MFA systems commonly ask for authentication factors in multiple stages. Most systems will request a password as a primary authentication factor.
- Secondary Authentication: Next, the user will be asked for a second authentication factor, such as an OTP. This might be generated by an app or sent to the user upon request.
- Verification and Access: The authentication server verifies that the provided factors are correct. If so, it checks that the user is authorized to make the request and grants or denies access accordingly.
Challenges and Considerations for Using MFA
MFA can dramatically improve account security by reducing the risk of account takeover attacks. However, it does come with challenges and important considerations, including:
- User Experience: MFA introduces additional steps to the user authentication process, which can create friction and degrade the user experience. One alternative is to use step-up authentication, which only requires additional authentication factors for higher-risk actions.
- Implementation Overhead: Some existing software may have built-in authentication functionality that assumes traditional, password-based authentication will be used. Implementing MFA might require significant software rewrites.
- Infrastructure Requirements: Some forms of MFA may require access to certain hardware, such as smartphones, fingerprint scanners, or smart card readers. Additionally, the company may need infrastructure in place to send OTPs to users.
Best Practices for Implementing MFA
Some best practices for an MFA implementation include:
- Implement MFA for all corporate applications.
- Choose more secure authentication factors where possible.
- Educate users about MFA and its benefits.
- Design MFA to meet compliance requirements.
- Use step-up or adaptive authentication to balance usability and security.
- Deploy MFA in stages to simplify troubleshooting and reduce downtime.
- Using standard implementations and protocols where available.
FAQ
What is the most secure MFA option?
Biometric authentication is the most secure option for authentication since it is the hardest to duplicate. However, it also can be challenging to implement due to privacy and security concerns.
What are some technologies driving MFA?
Multi-factor Authentication (MFA) is powered by several advanced technologies that enhance security while balancing the user experience. A few examples are:
- Fingerprint Recognition: Used on smartphones, laptops, and security key devices for identity verification.
- Facial Recognition: Apple’s Face ID, Windows Hello, and similar solutions use AI-driven facial mapping.
- Authenticator Apps (TOTP): Google Authenticator, Microsoft Authenticator, and Authy generate time-sensitive codes.
- Passkeys (FIDO2 Standard): Enables users to log in using biometrics or PINs instead of passwords.
- Magic Links: Sends a time-limited link via email or SMS for authentication without a password.
- QR Code-Based Authentication: Users scan a QR code with their mobile app to verify identity.
There are several others, but they all point to various MFA options available for enhanced authentication and security.
What is an example of a 3-factor authentication?
Three-factor authentication usually uses one of each of the main types of authentication factors. This could include a password (“something you know), OTP (“something you have”), and facial recognition (“something you are”).
What is the difference between authentication and MFA?
Essentially they are the similar in they require a user name and a password for authentication. MFA goes one step further by requiring additional verification of a user’s identity. This requires a second or third type of authentication such as OTP generated by a smartphone or authentication app, QR code, or biometrics, to name a few.
Leverage MFA With Cato Networks
Robust access management is essential to a strong cybersecurity program. Without the ability to conclusively prove a user’s identity, it’s impossible to differentiate between legitimate and unauthorized access attempts and actions. MFA can enhance an organization’s ability to authenticate customers and employees alike by reducing the risk of account takeover attacks.
Cato helps organizations secure remote access to their systems and applications by offering MFA by default for secure remote access solutions. To learn more about enhancing your organization’s network security with Cato SASE Cloud and how implementing MFA can help your organization achieve compliance and Zero Trust goals, sign up for a free demo.