How can multi-factor authentication design patterns and models improve security and usability?

1 Authentication factors

The first step in designing MFA solutions is to understand the different types of authentication factors that can be used. Authentication factors are usually classified into three categories: something you know, something you have, and something you are. Something you know refers to information that only the user knows, such as a password, a PIN, or a security question. Something you have refers to a physical or digital object that the user possesses, such as a smartphone, a token, or a card. Something you are refers to a biometric characteristic that the user exhibits, such as a fingerprint, a face, or a voice.

2 Authentication flows

The next step in designing MFA solutions is to determine the authentication flows that will be used. Authentication flows are the sequences of steps and interactions that the user follows to provide the authentication factors, and there are different ways to design them depending on the context, risk level, and user preferences. Step-up authentication requires the user to provide one factor initially, and then another factor when a higher level of security is needed. Adaptive authentication adjusts the number and type of factors based on user behavior, device, location, and other factors. Single sign-on (SSO) allows users to provide one factor once, and then access multiple systems or services without repeating the authentication process.

3 Authentication models

The final step in designing MFA solutions is to choose the authentication models that will be used. Authentication models are the ways that the system verifies the authentication factors that the user provides, and can vary depending on the architecture, performance, and scalability. Examples of authentication models include centralized authentication, where a single authority or service manages and verifies all the authentication factors; decentralized authentication, where some or all of the authentication factors are delegated to other authorities or services; and distributed authentication, in which some or all of the authentication factors are distributed across multiple nodes or peers. MFA is an effective security measure; however, it must be designed and implemented carefully to avoid compromising usability. By using different design patterns and models, system architects can create MFA solutions that balance security and usability for varying scenarios and needs.

4 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?