Single sign-on (SSO) isn’t just for convenience. It’s a critical layer of security, usability, and scalability for modern applications.
In simple terms, SSO lets users log in once and access multiple apps or services without re-authenticating for each. It allows users to access different applications with one set of login credentials. Instead of managing separate identities for each app, users sign in once through a trusted identity provider (IdP) and gain secure access across systems.
But in 2025, SSO plays a bigger role: It reduces password fatigue, supports zero trust security strategies, and helps teams manage user identities across sprawling SaaS environments.
In this guide, we’ll unpack how SSO works, explore core protocols like SAML and OAuth 2.0, and highlight why SSO is foundational to identity and access management (IAM) and overall security. You’ll also see how Frontegg simplifies SSO implementation for SaaS teams so you can ship secure, user-friendly login flows without months of engineering overhead.
Single sign-on is becoming essential for modern organizations facing rising identity and security challenges. Key reasons include:
But here’s what most organizations miss: SSO isn’t just a tool for IT. At Frontegg, we believe identity should be a shared responsibility across teams. By democratizing power over access control, product, security, and customer-facing teams gain more autonomy and SSO becomes a force multiplier. Developers can focus on building, while the rest of the org can manage users and permissions without bottlenecks.
This is part of an extensive series of guides about Access Management.
In this article:
SSO establishes trust between applications and a centralized IdP. When a user first tries to access an app, the IdP steps in to authenticate them and issues a secure token that can be used across other trusted services.
Here’s how the SSO process typically works:
Once authenticated, the user can access other applications in the trusted SSO network without logging in again.
Behind the scenes, this model reduces reliance on repeated credential entry, centralizes authentication control, and helps maintain session continuity, making it easier to manage user access at scale.
In an SSO system, once a user logs in through an IdP, the system issues an authentication artifact (such as an SSO token, assertion, or ticket) that can be passed to other applications, allowing access without requiring another login. They’re a core part of the trust relationship between the IdP and the service providers in an SSO system.
Two common types of authentication artifacts used in SSO are:
Access tokens: Used with OAuth 2.0 and OIDC, these are passed along with requests and grant access to protected resources.
SAML assertions: XML-based artifacts that pass authentication and authorization data between the identity provider (IdP) and the service provider (though not all of that data is necessarily intended for the service provider itself).
The token lifecycle includes several key steps:
These tokens are encrypted and time-bound to protect against unauthorized access. If compromised, they can be revoked or expire automatically, helping reduce security risks while keeping the login experience smooth for end users.
The key benefits of single sign-on are:
Different SSO protocols support different environments, from cloud-native SaaS platforms to legacy enterprise systems. Understanding these standards helps technical teams choose the right fit and gives decision-makers clarity on what’s powering their access control.
SAML is an XML-based open standard widely used in enterprise web applications. It enables secure communication between an IdP and a service provider by sending authentication and authorization data through browser redirects. It’s especially common in B2B settings and supports federated identity management across organizations.
OIDC is an identity layer built on top of OAuth 2.0, designed for modern web and mobile applications. It uses lightweight JSON tokens and supports features like social login and identity verification. OIDC is ideal for customer-facing SaaS apps where performance and scalability are critical.
OAuth 2.0 is an open standard for token-based authorization. While not an authentication protocol on its own, it plays a central role in issuing and managing access tokens. OAuth lets users grant limited access to apps without sharing their credentials, making it a key part of the SSO process.
Kerberos is a ticket-based protocol commonly used in on-premises environments like Windows domains. It allows secure mutual authentication between users and services using a centralized ticket-granting server. While older, Kerberos remains essential in legacy enterprise IT infrastructures.
LDAP (Lightweight Directory Access Protocol) is a standard for accessing and managing directory information. When paired with Microsoft Active Directory, it provides centralized user identity storage and is often used to enable SSO across internal tools and systems. It remains popular in hybrid cloud or fully on-prem environments.
The table below compares the common SSO protocols described in this section for an at-a-glance view:
While social logins, using platforms like Google, Facebook, or LinkedIn as identity providers, can streamline sign-up and access for consumers, they come with tradeoffs that limit their usefulness in enterprise environments.
Social login pros include:
Social login cons include:
While social login simplifies access, it centralizes identity control under third-party providers, which can introduce vulnerabilities. As Jason Polakis, a security researcher at the University of Illinois at Chicago, explains, “In general, I’m against consumer SSO schemes because they not only present a single point of failure, but because they also enable additional attacks that are not feasible with traditional password‑based authentication.”
By contrast, enterprise SSO gives organizations more control over user authentication, permissions, and auditability. It connects apps to a centralized, trusted identity provider, typically using protocols like SAML or OIDC, and supports security features like multi-factor authentication (MFA) and role-based access control (RBAC).
For businesses that need to manage user identities securely at scale, enterprise-grade SSO is a security and compliance essential.
Implementing SSO successfully starts with preparation and ends with a secure, seamless experience for users. Whether you’re building a new application or modernizing internal systems, these five steps will help your team get SSO right:
Done right, SSO boosts both security and productivity without slowing down development or overburdening IT.
While single sign-on offers major benefits, it’s not without its friction points. Organizations implementing SSO should be aware of the potential risks and roadblocks, most of which stem from configuration issues or a lack of planning.
When done right, SSO is a win for both security and usability. But without proper planning, it can introduce new risks. That’s why Frontegg helps teams deploy SSO with smart defaults, flexible integrations, and clear visibility into user behavior so you’re never flying blind.
For most SaaS teams, implementing single sign-on means weeks of development, custom integrations, and ongoing support requests. Frontegg changes that.
With just a few lines of code, you can integrate full-featured SSO functionality into your app, supporting protocols like OIDC, SAML, and social login out of the box. Your users authenticate seamlessly, while your developers stay focused on building the product, not handling identity tickets.
Frontegg also puts control in the hands of your customers. With self-serve admin tools, they can configure their own SSO setup, connect to their preferred identity providers, manage user permissions, and update access settings without waiting on your team.
From faster deployment to a more secure user experience, Frontegg gives you the tools to make SSO simple, scalable, and user-friendly for everyone involved.
In 2025, SSO is foundational to every business. It simplifies access for users, reduces overhead for IT, and tightens security in a world where login credentials remain a top attack vector.
But SSO is just one part of a larger IAM strategy. As teams adopt more SaaS tools, support hybrid workforces, and prioritize zero trust security, modern IAM needs to do more than authenticate users; it needs to empower the entire organization to manage identity without friction.
Frontegg helps you get there. By giving developers the tools to implement SSO quickly and enabling product, customer success, and security teams to manage access without code, Frontegg removes the bottlenecks that slow teams down.
Identity doesn’t have to be a burden. With Frontegg, it becomes a growth enabler: secure, seamless, and ready to scale.
Ready to streamline identity for your app? Get started with Frontegg.
Together with our content partners, we have authored in-depth guides on several other topics that can also be useful as you explore the world of access management.
Authored by Frontegg
Authored by Faddom
