TL;DR
Traditional passwords alone are no longer sufficient to protect organizational systems. While Universal 2nd Factor (U2F) hardware keys provide strong authentication assurance, their physical nature makes them costly, difficult to manage, and incompatible with mobile devices. Adaptive Multi-Factor Authentication (AMFA) — which dynamically adjusts security policies based on device, location, and user context — offers a more flexible and operationally practical alternative for most organizations.
How do you protect employees working from everywhere?
Providing your users with the freedom to log in to your organization's systems from anywhere is almost a mandatory requirement in today's modern workplace. Remote access is a business enabler — it drives efficiency by improving collaboration and productivity in your organization — but unfortunately providing this necessary access can also expose your systems and increases the risk of compromise. U2F can provide you with an additional layer of security, but is it an effective and practical solution to this problem?
Why is traditional authentication no longer enough?
For many organizations, the only thing protecting them from a full system compromise are usernames and passwords. Authentication systems are constantly being probed for weaknesses by a variety of threat actors, ranging from the lone curious hacker to a nation state. Phishing campaigns, credential stuffing, and a host of other sophisticated password cracking techniques target your users' credentials looking to leverage weak passwords and weak password management.
Why is MFA the best defense?
MFA is the best defense against automated password attacks and phishing campaigns. It adds an additional layer of access security during the authentication process. This reduces your organization's risk of a system breach by requiring users to submit an authentication factor, such as a one-time password (OTP) or physical device over and above their required password.
There are a range of MFA solutions that can help secure your authentication systems. These range from low to high assurance:
- Low assurance: simple security question
- Medium assurance: one-time password (OTP)
- High assurance: U2F keys
What is Universal 2nd Factor (U2F)?
U2F is an open authentication standard that was initially developed by Google and Yubico. The standard, which is now hosted by the Fast IDentity Online (FIDO) Alliance, is used in U2F security keys — physical security devices you plug into a USB port after submitting your username and password. They provide an effective second authentication factor as without the physical device being plugged in, authentication fails and access is denied.
U2F devices rank high on the authentication assurance scale. The use of an asymmetric encryption algorithm ensures this authentication token can never be compromised — the private key never leaves the device.
What are the limitations of U2F keys?
While there's no question that U2F keys offer an effective layer of protection against password attacks, they do have their drawbacks. The main challenge is the requirement of carrying around another piece of hardware. They can fail, or be misplaced or stolen, which impacts system usability, and in some instances, compromises security. In addition, U2F keys need USB ports. This USB prerequisite renders U2F an untenable solution for mobile devices as most, if not all, have no USB ports.
How does adaptive MFA add context to the authentication flow?
Adaptive Multi-Factor Authentication (AMFA) improves the security of your systems by taking the context of an authentication request into account. Leveraging multiple factors at the time an access request is made, it provides an additional layer of protection that dynamically adapts security and authentication policies based on user and device context.
How does Okta's Adaptive MFA use context?
Okta's Adaptive MFA receives contextual information at the time of an authentication request, including:
- Device
- Location
- IP address
- Client type
Taking this input into account, it compares this data to predefined policies set in your Okta Policy Framework and either grants access, denies access, or prompts the user to submit an additional form of identity verification.
Should you choose U2F or adaptive MFA?
U2F and AMFA are both effective solutions that mitigate the risks posed by password-based authentication solutions. However, if we look at the practicality of implementing each solution, AMFA is the better option as it is not hardware reliant.
Why is AMFA the more practical choice?
U2F requires you to purchase a physical device for every user in your organization, configure these, and then distribute them. Not only is this a costly exercise, it takes time and effort and constant management post-implementation phase. AMFA on the other hand is a cloud-based solution, which enables greater operational flexibility. It is also easier to implement, simpler to manage, and is ultimately more cost effective.
| Criterion | U2F | Adaptive MFA (AMFA) |
|---|---|---|
| Hardware Required | Yes — physical USB security key required | No — cloud-based solution |
| Cost | Higher — must purchase, configure, and distribute a device per user | Lower — no hardware costs; easier to scale |
| Mobile Compatibility | No — requires a USB port, which most mobile devices lack | Yes — not hardware dependent |
| Ease of Implementation | More complex — requires physical distribution and configuration | Easier to implement |
| Management Complexity | Higher — ongoing management post-implementation required | Lower — simpler to manage |
| Authentication Assurance | High — asymmetric encryption; private key never leaves the device | High — dynamically adapts based on device, location, IP address, and client type |
Frequently asked questions
What makes traditional password-based authentication vulnerable?
Passwords alone leave systems exposed to a range of attacks, including phishing campaigns, credential stuffing, and sophisticated password-cracking techniques. Threat actors — from individual hackers to nation-states — continuously probe authentication systems for weaknesses, making usernames and passwords an insufficient sole defense.
How does multi-factor authentication (MFA) reduce the risk of a system breach?
Multi-factor authentication (MFA) requires users to provide an additional verification factor — such as a one-time password (OTP) or a physical device — beyond their standard password. This extra layer means that even if credentials are compromised, unauthorized access is still blocked.
What is a Universal 2nd Factor (U2F) security key and how does it work?
A Universal 2nd Factor (U2F) security key is a physical device that plugs into a USB port. After entering a username and password, the user must also have the key physically connected for authentication to succeed. It uses asymmetric encryption, meaning the private key never leaves the device, making it highly resistant to remote compromise.
Why are Universal 2nd Factor (U2F) keys not suitable for mobile devices?
Universal 2nd Factor (U2F) keys require a USB port to function. Since most modern mobile devices do not have USB ports, U2F is effectively incompatible with mobile authentication scenarios, limiting its practicality in mobile-first or hybrid work environments.
What contextual factors does Adaptive Multi-Factor Authentication (AMFA) evaluate when granting access?
Adaptive Multi-Factor Authentication (AMFA) assesses several contextual signals at the time of an authentication request, including the user's device, geographic location, IP address, and client type. This data is compared against predefined policies to determine whether to grant access, deny it, or prompt for additional verification.
Why is Adaptive Multi-Factor Authentication (AMFA) considered more cost-effective than Universal 2nd Factor (U2F) for most organizations?
Unlike Universal 2nd Factor (U2F), which requires purchasing, configuring, distributing, and continuously managing a physical device for every user, Adaptive Multi-Factor Authentication (AMFA)is a cloud-based solution. This eliminates hardware costs and reduces the ongoing operational burden, making it easier to implement and scale across an organization.
