Two-Factor Authentication
Two-Factor Authentication refers to an authentication method where exactly two different factors must be presented by a user, before access is granted to IT assets such as an online account or application. Also known as 2-Factor Authentication or 2FA, it has become a staple within cybersecurity best practices and a pillar of Identity and Access Management (IAM).
Two-Factor Authentication Definition
Two-Factor Authentication requires exactly two forms of identification from an array of defined credential categories, to verify a user before a transaction or login is permitted. Commonly, two-factor authentication solutions do this by first requesting the unique password linked to the account as the first authentication factor. Thereafter, the second authentication factor can be many additional things, such as a fingerprint, an OTP provided through a text message, or a hardware security key, among others. Although methods vary and ultimately dictate the overall strength of the solution, the two-factor authentication definition only stipulates that the first and second authentication factors must not be the same and are generally from different categories.
Two-Factor Authentication FAQs
How Does Two-Factor Authentication Work?
The best way to answer the question of how does two-factor authentication work is to illustrate the different ways someone can validate their identity. All authentication factors fall into one of three different categories:
- Something You Know – For example, a unique password or PIN.
- Something You Have – For example, a physical device like a phone, ID card or hardware security key.
- Something You Are – For example, a physical feature such as a fingerprint or iris signature.
Throughout most of IT history, people have only needed to provide one authentication factor, being the common password. But as access control, system architecture and ecosystems have drastically increased in complexity, in parallel with the sophistication of attackers, cybersecurity now requires a much more secure approach to deal with modern security risks. Efforts to carefully restrict access to sensitive IT resources to only those with explicit authorization, have prompted the shift to two-factor authentication, which is increasingly becoming the norm for accessing anything of significance.
What is the benefit of Two-Factor Authentication?
Two-factor authentication is not considered weak like single factor authentication, especially when passwords are the only factor, and is generally magnitudes stronger as a security mechanism. Cyber criminals have become very proficient at stealing passwords at scale, from phishing attacks, social engineering, and malware, to simply guessing weak passwords or in some cases, using default ones. Weak or stolen passwords play a role in 81% of all data breaches, and those breaches affect organizations in worse ways than ever before, in an age where customer data and reputation are among the most valuable commodities in the modern digital economy.
Adopting two-factor authentication helps companies also meet increasing compliance obligations around cybersecurity, such as those arising from the EU, US Federal and cyber insurance industry. The ability to nominate the factors used in two-factor authentication gives flexibility to access control that makes life easier for users, but also potentially reduces costs for enterprises in hours and resources spent by admins and support staff. Last but certainly not least, effective access control can neutralize the vast majority of attacks to take pressure off the teams and tools responsible for cyber defense. Two-factor authentication doesn’t just add another step to login – it makes organizations more formidable against the greatest risks they face in a connected world.
What are the disadvantages of Two-Factor Authentication?
The disadvantages of two-factor authentication have less to do with the concept itself and more to do with the execution. Clearly, a technical deployment is required to elevate a solution from single factor to two-factor, which may result in upfront product implementation and technical support costs. In other cases, factor combinations may deliver stronger security, easier accessibility, and simpler management, but may carry higher ongoing costs than others. An example is using OTP delivered via SMS, which may bear telecommunication costs from the service provider.
While moving to two-factor authentication is always a step in the right direction and represents a significant security upgrade over single factor authentication, it can create unexpected issues without the proper planning and management. However, with the right two-factor authentication products, policies and processes in place, it has effectively no disadvantages.
How to get started with Two-Factor Authentication?
The process starts with first investigating whether two-factor authentication is available on all of the apps used within your environment or ecosystem. Most apps these days have a setting to enable two-factor authentication, and while it is often encouraged, it is not the standard or default option in most cases. Ideally, enable two-factor authentication on apps, admin accounts, clouds, and anything else where the option exists, and where it does not exist, plan to transition to solutions that make access security a bigger priority by offering 2FA at a minimum.
The next step is choosing which two factors to use. For practical and legacy reasons, passwords are usually the first factor and cannot be removed, even if they are far from optimal. Therefore, the choice of the second factor is generally more impactful because some options are stronger than others, and it can offset or augment the weakness created by passwords. For example, sending an OTP to a mobile device is a common second factor – common enough that hackers have now become proficient at stealing or intercepting these, ultimately undermining its strength as a second factor. Biometric authentication on the other hand, is much harder to compromise remotely and represents a step towards stronger authentication. Stronger still, and the overall best combination of both security and accessibility, generally comes from smart cards and hardware security keys. Still, an important part of the process will be evaluating and choosing between the various options based on the requirements of the users and enterprise.
The final and often neglected step when introducing two-factor authentication is education, training and learning to get into the habit of using stronger forms of authentication. Productivity, continuity, and buy-in depends on making users feel comfortable with two-factor authentication. Begin by stressing the importance of access control and the widespread risks of poor cybersecurity. Next, cover exactly how two-factor authentication will work, both in everyday and edge cases. Finally, provide ongoing support and updated training so that access controls don’t become an obstacle or annoyance but a good habit.
What are the different types of Two-Factor Authentication Solutions?
Deciding which two factors to use leads into the question of which specific two-factor authentication solutions should enterprises and users gravitate towards. The right solution should consider strength, ease of use and cost. Here’s how some popular two-factor authentication solutions compare:
- Smart Cards – Also referred to as Personal Identity Verification (PIV) cards, this option is considered extremely robust in terms of security because a hacker would need to steal or replicate a physical card in order to authenticate themselves. The downside is that this solution requires a card reader (or multiple readers), which can be expensive to implement. Further, a Credential Management System (CMS) is required to provision and manage the credentials which reside on each of the cards, which can be difficult for large or remote workforces.
- Hardware Security Keys – Authenticators with FIDO2 or passkey capabilities that can be inserted into a USB port or tapped against an NFC reader attached to a computing device. These devices have the same upside as security cards while generally being easier to use and manage since a CMS is not required. Credentials are only valid between the hardware security key itself and individual services or relying parties, but multiple such relationships can reside on a single hardware security key.
- OTP Solutions – Generally considered both easy to use and implement, and certainly more secure than passwords, sending an OTP to a phone number or email address has, unfortunately, become weak as attackers have become adept at stealing or intercepting this information, and dead batteries or lost phones can also make access difficult in other cases. Even having to transcribe the info from the source to the app or screen can raise accessibility issues, and the telecommunication carrier costs are also a consideration. Trends within two-factor authentication suggest many implementations are moving away from OTP to other solutions, due to the aforementioned reasons.
- Authenticator Apps – Apps that generate a mobile push notification which then require a user to acknowledge or accept it. Similar to OTP solutions delivered through SMS, relying on a phone makes authentication dependent on network connectivity, battery life, and having physical access to the phone in the first place. While generally easy to use, these however, may also be susceptible to spamming or fatigue attacks.
Two-Factor Authentication vs Multi-Factor Authentication
Differentiating between two-factor authentication and multi-factor authentication (or MFA) can cause a lot of unnecessary confusion. With two-factor authentication, as the name implies, there are exactly two factors – not more or less. With multi-factor authentication, there only needs to be at least two factors, which could mean two, three or even more. Two-factor authentication is a subset of multi-factor authentication, but not all versions of multi-factor authentication will qualify as two-factor authentication.
Two-Factor Authentication vs. Two-Step Authentication
It’s not uncommon to hear the terms two-factor authentication and two-step verification used interchangeably. And while they are very similar concepts, they are not identical, and the difference is critical.
As discussed already, two-factor authentication relies on two distinct forms of authentication such as a password and a hardware security key, or a smart card with a PIN. The term two-factor authentication specifically designates that the first and second factor are not the same so that bad actors will have more challenging obstacles to clear when trying to compromise access.
With two-step authentication, the same category of factor can actually be repeated twice. An example would be an authentication process that asks for a password (something you know) followed by a security question (something else you know). While two-step authentication is more secure than single factor authentication because users must clear a higher bar to gain access, it is far less secure than two-factor authentication because hackers may be able to use similar tactics or avenues to compromise both steps.
Is Two-Factor Authentication Completely Secure?
It’s impossible to eliminate all risk, and cybersecurity can never be perfect. As such, there are definitely scenarios in which hackers could break through two-factor authentication to access sensitive digital resources. However, it’s important to put that risk in context.
Hackers rarely seek out a specific target, but rather seek out the path of least resistance, aiming at whatever target seems most vulnerable first, and then maneuvering thereafter. This means password-based solutions will generally be a target before others with two-factor authentication. While 2FA does more to reduce overall cyber risk and enhance total cyber defenses, it is generally effective enough especially given how easy and economical it can be to enable two-factor authentication on most solutions or apps.
Does Yubico Offer Two-Factor Authentication?
Yubico has been a pioneer, innovator, and longstanding leader in two-factor authentication. We created the YubiKey, a hardware security key that can serve as one of the authentication factors. YubiKeys come in various form factors, price points and capabilities, but in all cases, they ensure that the only user who can gain access is the user holding the physical device.
As a component within a multi-factor authentication solution, the YubiKey has a number of unique and important features. From a security standpoint, it makes unauthorized remote access extremely difficult due to the use of asymmetric cryptography, reducing cyber risk over networks significantly. The cost and technical requirements to implement the YubiKey are also less than most alternatives offering the same strength of security, making it a smart solution for enterprises with limited cybersecurity resources. Finally, hardware security keys are easy to adopt, user friendly and they open the door to a passwordless future where access is more seamless (and secure) than ever.
Find out more about Yubico’s Two-Factor Authentication here.
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