Single Sign-On (SSO)
Managing many sign-in credentials is tedious and carries increased security risks. Single Sign-On (SSO) allows users to access multiple applications through one set of credentials to improve both user experience and security.
There are two common forms of SSO: enterprise and social. With enterprise SSO, employees are required to access applications by signing in through their employee directory, usually Microsoft Active Directory, Google Workspace, or Okta. With social SSO, users are given the option to sign in through an account they already have with a different service, like the “Sign in with Google” button.
What is single sign-on
At the highest level, SSO is the process of signing into one application using the details of an account with another application. The same foundational technology is used in two distinct contexts: enterprise SSO and social SSO.
With enterprise SSO, employees are forced to sign into tools and services using their employee directory account. This is mandated by IT teams, since it makes it easier to provision and pay for those tools, as well as ensure that employees only have access to the tools they absolutely need.
With social SSO, any application can give users the option to sign into the application using an account that they already have, normally with a popular provider like Google. This takes the form of a “Sign in with Google” button on a sign-in screen, and is usually offered because it reduces friction during sign-up and sign-in.
How SSO works
There are three main protocols used to facilitate SSO: SAML, OAuth 2.0, and OpenID Connect. SAML is only used in enterprise SSO contexts, while OAuth 2.0 and OpenID Connect are used in both enterprise SSO and social SSO contexts.
Each protocol relies on similar concepts. The application being signed into is considered the Service Provider (SP), while the application being relied on for account details is considered the Identity Provider (IdP).
When a user accesses a SP, they're redirected to the IdP for authentication. After success, the IdP communicates the user's profile data back to the SP according to the selected protocol.
The primary difference between the protocols is their rigidity. SAML can be configured in many ways, while OAuth 2.0 can be configured in fewer, and OIDC is rigid. In fact, OIDC is an extension of OAuth 2.0 that standardizes specifically how it should be used for authentication, since the broader OAuth 2.0 protocol is flexible enough to also be used for authorization.
For developers, the rigidity translates into simplicity, and OIDC has been growing in popularity as a result. OIDC uses JSON Web Tokens (JWTs) as a streamlined, secure, and standardized mechanism for transmitting user details.
Security measures protect the SSO process through token encryption, expiration policies, and multi-factor authentication. These measures prevent unauthorized access and maintain smooth authentication across applications. The combination of security features and simplified access makes SSO effective for modern application architectures.
Comparison with other authentication strategies
Single Sign-On (SSO) is one of several approaches to authentication, each offering different benefits and drawbacks. Here’s a look at how SSO compares to other strategies like Password Authentication and Email One-Time Passcode Authentication:
Password authentication
Password authentication remains the most prevalent method of authenticating users. Users create a password that is used to gain access to an application, and sign in with it alongside an identifier, like a username or email address.
Despite its widespread use, password authentication carries notable drawbacks. Passwords can be weak, reused, or even compromised in data breaches, leading to a security risk. Implementing strong password policies and hashing techniques can mitigate some risks, but the convenience factor often falls short for users.
Password authentication also requires ongoing management, such as password leak detection and password recovery mechanisms. Despite its drawbacks, many applications still rely on password-based methods due to their simplicity and familiarity to users.
Email one-time passcode authentication
Email one-time passcode (OTP) authentication offers a more secure alternative to passwords by issuing temporary codes to users. By sending a single-use code to the user’s registered email address, OTP enhances security compared to static passwords, reducing risks like replay attacks. The dynamic nature of OTPs means they have a limited lifespan, minimizing the potential for abuse.
However, email OTPs require an email to be delivered, and the user to open their email to retrieve the code. This process adds a significant delay to the authentication process that SSO and passwords do not have.
Choosing the right strategy
SSO excels at providing a simplified user experience by reducing the need for multiple credentials. In contrast, password authentication is common but less secure, while OTP-based solutions offer security improvements but are often too slow. Applications should weigh their specific requirements to choose the most suitable authentication strategy.
Enterprise SSO
Enterprise SSO is a specialized implementation of single sign-on focusing on large organizations with complex authentication needs. Enterprises often need strong identity management systems that integrate with existing infrastructure and adhere to strict security and compliance standards.
Enterprise environments often use protocols like SAML, which support centralized authentication across diverse applications and systems. Enterprise SSO solutions must accommodate multiple user accounts, roles, and permissions to fit within organizational structures. They address requirements such as scaling, integration with on-premise systems, and providing access to cloud services.
Clerk and enterprise SSO
Clerk offers enterprise-ready SSO solutions for businesses requiring advanced security and compliance. Clerk supports enterprise connections using SAML, allowing organizations to integrate with identity management systems like Microsoft Azure Entra ID.
To create a SAML connection in Clerk, developers configure their identity provider and service provider settings within the Clerk Dashboard. Clerk supports both service provider-initiated and identity provider-initiated flows, which offer flexibility in deployment scenarios.
Clerk ensures enterprise-grade security protections such as CSRF and XSS protection, session fixation, and password safety through industry-standard practices. Enterprises can utilize Clerk's session architecture and support for multiple accounts and devices to fit into complex environments without sacrificing performance or security.
Clerk's EASIE SSO solution further elevates enterprise SSO by offering a multi-tenant OpenID provider, blending simplicity and strong security features. EASIE allows for effortless setup with email domain-based enrollment and mandatory sign-ins through designated OIDC providers. This streamlined setup eliminates SSO fees, making enterprise SSO more accessible and efficient. With plans to expand its adoption across various industries, EASIE SSO enables organizations to manage user authentication, providing a smooth experience with heightened security.
Social SSO
Social SSO simplifies the sign-in process by allowing users to sign in to applications using their existing accounts from popular platforms like Google, Facebook, or GitHub. This approach is particularly useful for consumer-facing applications where reducing friction during user sign-up and sign-in is important.
Integrating Social SSO can improve user experience and reduce drop-off rates during sign-up, and provides a smooth transition for users already signed into their social accounts. Clerk supports a wide range of Social SSO providers, enabling developers to integrate with a single click and configure high-conversion authentication options that are ready out of the box.
As users demand more convenient access methods, integrating Social SSO represents a strategic choice for applications aiming to broaden their user base while maintaining strong security measures.
Moving Forward with SSO
SSO is a standard for modern applications prioritizing security and user experience. Its ability to centralize authentication, reduce password management, and strengthen security is valuable. The scalability of SSO, supported by protocols like SAML and OpenID Connect, provides a foundation for growing ecosystems.
For teams ready to implement SSO, Clerk offers a reliable starting point. Clerk's documentation and support resources help developers understand implementation difficulties and create secure authentication flows. By leveraging Clerk's SSO features, teams can focus on building applications while providing users with a smooth authentication experience.