Security Keys and Two-Factor Authentication: What Level of Protection Does Your Business Really Need?

Two-factor authentication has become a standard security recommendation. Many organisations consider it a box they have already ticked. A code sent to a phone. A push notification to approve a login. A second step added to the process.

While this is a positive move, it has created a false sense of security. Not all multi-factor authentication provides the same level of protection. Some methods add friction without meaningfully reducing risk. Others significantly raise the bar for attackers.

The hidden problem is simple. Not all MFA protects equally.

Using two-factor authentication is a good start, but the type of MFA matters. SMS codes and basic approval prompts are increasingly easy to bypass, while stronger methods such as security keys provide far higher assurance. Real protection comes from matching authentication strength to business risk.

Why SMS Codes Are No Longer Enough

SMS based authentication was once considered a strong improvement over passwords alone. Today, it is widely recognised as one of the weakest forms of MFA.

SMS codes can be intercepted through SIM swapping, number porting fraud, or malware on mobile devices. Messages can be delayed, redirected, or accessed without the user realising it. In some cases, attackers do not even need to intercept the message. They simply trick the user into sharing the code.

From a security perspective, SMS adds a second step, but not a strong second factor. It still relies heavily on human behaviour and vulnerable telecommunications infrastructure.

For low risk consumer services, this may be acceptable. For business systems that handle sensitive data, it is often not.

How Attackers Bypass Weak MFA

Attackers rarely attempt to break systems head on. They look for the easiest path in.

With weak MFA, that path often involves social engineering. Phishing pages that request both a password and an SMS code. Phone calls pretending to be IT support. Fake login prompts designed to harvest approval responses.

One increasingly common tactic is MFA fatigue. Attackers trigger repeated login attempts, sending multiple push notifications to the user. Eventually, the user approves the request just to stop the alerts, unknowingly granting access.

In these scenarios, MFA is technically enabled, but functionally ineffective. The attacker does not need to defeat the system. They only need to exploit human reaction.

The difference between convenience MFA and security MFA

Not all MFA is designed with the same goal.

Convenience focused MFA prioritises ease of use. It reduces friction but often assumes the user will always act correctly. SMS codes and simple push approvals fall into this category.

Security focused MFA prioritises assurance. It reduces reliance on user judgement and makes unauthorised access significantly harder, even if a user is targeted or distracted.

The difference matters. Convenience MFA can slow attackers down. Security MFA can stop them altogether.

Understanding this distinction is critical when deciding how much protection is actually required.

When Security Keys Actually Make Sense

Security keys provide one of the strongest forms of multi-factor authentication available today. They work by using cryptographic proof tied to a physical device. The key must be present and actively used to complete authentication.

This makes common attack methods ineffective. Phishing pages cannot capture a usable credential. Approval bombing does not work. SMS interception is irrelevant.

Security keys are not necessary for every system or every user. They are most effective when applied where the impact of compromise would be high.

Examples include administrators, executives, finance teams, access to sensitive systems, and environments with regulatory or compliance obligations.

In these contexts, the added assurance far outweighs the minor inconvenience of an extra device.

Who Needs Stronger Authentication And Who Does Not

Not every employee needs the same level of authentication strength. Treating all access equally often leads to unnecessary friction or underprotection.

High risk roles and systems require stronger controls. Low risk access may be adequately protected with simpler methods.

The key is understanding risk. What systems would cause the most damage if compromised. What roles have broad access. Where data sensitivity or regulatory exposure is highest.

Effective authentication strategies are layered, not uniform.

MFA Fatigue And Approval Bombing Risks

Push based authentication has introduced a new class of risk. When users are asked to approve login requests without context, security depends on their attention and judgement.

Attackers exploit this by sending repeated requests until one is approved. This is not a failure of the user. It is a failure of the authentication design.

Stronger MFA methods remove this burden. They do not ask users to make security decisions under pressure. They require proof that cannot be accidentally or impatiently granted.

Reducing decision fatigue is an often overlooked aspect of improving security.

Matching Authentication Strength To Business Risk

The most effective security strategies are proportional. They do not apply the strongest controls everywhere. They apply the right controls where they matter most.

Authentication strength should be matched to the potential impact of compromise. A low risk internal tool does not need the same protection as a financial system or administrative console.

By aligning authentication methods with risk levels, businesses improve security without slowing teams down or overcomplicating access.

This approach creates resilience rather than resistance.

Concerned that your current MFA setup may be adding friction without providing real protection? Book a free identity and access review, here, and gain a clear view of where your authentication methods fall short, where stronger options like security keys make sense, and how to match protection levels to real business risk.