Single Sign-On (SSO) and Multi-Factor Authentication (MFA) are two critical elements of modern enterprise security, but they are distinct technologies that serve different purposes. It’s a common misconception that SSO and MFA are interchangeable or that one includes the other. In reality, SSO and MFA work together to strengthen access security, but they are not the same thing.
In this article, we will explain what each solution is, why they are different, and how MFA can enhance the security of SSO deployments, particularly when accessing critical or sensitive applications.
What is Single Sign-On (SSO)?
Single Sign-On (SSO) is a user authentication process that allows an individual to access multiple applications and systems by logging in once with a single set of credentials. After the initial authentication, the SSO system manages subsequent authentication processes behind the scenes without requiring the user to log in again for each application.
The primary benefits of SSO include:
- Improved User Experience: Users avoid password fatigue from managing numerous credentials.
- Increased Productivity: Fewer login prompts mean users can access necessary applications more quickly.
- Reduced IT Burden: Lower volume of password reset requests.
- Better Compliance and Security Management: Centralised control over user access.
However, because SSO centralises access through a single authentication event, the security of that one event becomes critically important. If the SSO credentials are compromised, the attacker could potentially access all connected applications.
What is Multi-Factor Authentication (MFA)?
Multi-Factor Authentication (MFA) is a security enhancement that requires users to present two or more separate forms of verification before they are granted access. These factors typically fall into three categories:
- Something you know (e.g., a password or PIN)
- Something you have (e.g., a smartphone or security token)
- Something you are (e.g., fingerprint or facial recognition)
MFA significantly increases the difficulty for an attacker to gain unauthorised access, even if they have managed to obtain a user's password.
The benefits of MFA include:
- Stronger Security: It adds an additional barrier beyond the password.
- Reduced Risk of Credential Theft: Even if credentials are stolen, a second factor is required to access systems.
- Compliance with Regulatory Requirements: Many industry standards recommend or mandate MFA.
Why SSO and MFA are Different
While both SSO and MFA deal with user authentication, their functions are fundamentally different:
SSO is about convenience and efficiency. It streamlines access by reducing the number of times a user must authenticate.
MFA is about security and verification. It ensures that the person logging in is genuinely the account owner by requiring multiple forms of identification.
SSO simplifies access; MFA hardens it. Therefore, while they are often deployed together for a more secure and user-friendly experience, they are distinct technologies addressing different aspects of identity and access management.
How MFA Enhances SSO
Although SSO alone can streamline access, adding MFA to SSO deployments greatly improves their security posture. Enterprises can configure policies within their SSO solution to require MFA for specific scenarios, such as:
- Access to high-risk or sensitive applications (e.g., financial, HR, or customer data systems)
- Authentication from untrusted devices or locations
- Sign-in attempts outside normal working hours
- Elevated privilege actions within an application
By integrating MFA with SSO, organisations can create application-specific policies. For example, an employee may be allowed seamless SSO access to general productivity tools like email or collaboration platforms, but must pass an MFA check to access sensitive applications like payroll systems or client databases. This approach ensures elevated trust without introducing friction for lower-risk application use.
Importantly, by implementing adaptive authentication within the SSO system, enterprises can balance user experience and security. Low-risk scenarios may require only the primary SSO login, while higher-risk actions or critical app access trigger a prompt for an additional verification factor.
Overall, Single Sign-On and Multi-Factor Authentication are not the same. SSO simplifies and centralises access management, while MFA strengthens authentication security by adding layers of verification. Used independently, each has benefits and limitations. Used together, they create a secure and seamless user experience, especially when organisations apply intelligent policies that trigger MFA based on risk factors or application sensitivity.
How My1Login Helps
My1Login enables enterprises to benefit from Single Sign-On that is directly linked to the users’ directory authentication, and MFA where appropriate. Users just authenticate with the corporate directory (e.g. Entra ID, Active Directory etc) and My1Login will utilise this delegated trust to onward authenticate the user with all other external applications. This includes web and Windows desktop applications that typically would have required the user to enter credentials. My1Login can also automate the secure generation and entry of One Time Passwords (OTPs) where required by external applications if the user is already authenticated with the corporate directory.
For applications and services that contain more sensitive or critical data, elevated trust policies can be configured within My1Login to ensure either step-up or Multi-Factor Authentication challenges are satisfied before permitting access.
