What is single sign-on (SSO)?

How does single sign-on work?

Single sign-on is a component of federated identity management (FIM), an arrangement between enterprises that lets subscribers use the same identification data to access each enterprise’s network. FIM is often referred to as identity federation.

The user’s identity is linked across multiple security domains, each with its own identity management system. When the domains are federated, the user can authenticate to one and access resources in another without having to sign in again.

The framework that allows third parties, like LinkedIn or Facebook, to use someone’s account information to sign them in without exposing their password is called OAuth. It acts as an intermediary by providing the service with a token allowing only specified account information to be shared. When a user accesses an application, the service sends an authentication request to the identity provider, which then verifies the request and grants access.

There are other authenticating protocols, like Kerberos and the Security Assertion Markup Language (SAML). Kerberos-based SSO services issue a time-stamped authentication ticket, or ticket-granting ticket (TGT), which gets service tickets for other applications without prompting the user to enter new credentials. SAML-based SSO services exchange user authentication and authorization data across secure domains, and manage communications between the user, an identity provider with a user directory, and a service provider.

Single sign on best practices

When searching for an SSO solution, it’s important to keep the following best practices in mind.

1. Access to any application. Some SSO solutions are limited in the scope of application landscape they cover. Some on-premises solutions provide SSO to web and enterprise applications but cannot do the same for virtual desktop infrastructure (VDI) or SaaS applications. On the other hand, some of the IDaaS vendors provide SSO to cloud and SaaS applications but not for on-premises applications. When evaluating an SSO solution, you should prioritize the capability to not only provide SSO experience across all VDI, enterprise, web, and SaaS applications, but also network access to other corporate resources like network file shares.
2. Secure user identity when accessing SaaS applications. SaaS applications are outside of the data center network. To achieve SSO to these applications, many solutions require customers to move their user directory to cloud. This, to many enterprise customers, is a concern and a high-risk task, which is why your solution should provide the option to keep your user directory on premises.
3. Integration with multi-factor authentication mechanisms. It’s crucial to quickly and rightfully identify any user and authorize their access to corporate resources. Enterprise customers, therefore, should not rely on just usernames and passwords but should also look for a solution that provides flexibility to use authentication schemes based on the state of end user device, user location, application they are trying to access, etc. This makes it important to select an SSO solution that supports any authentication mechanism as well as authentication protocols like RADIUS, Kerberos, Microsoft NTLM, Certificate Services, etc.
4. Monitoring and troubleshooting tools. Your SSO solution should include monitoring tools that look for performance issues for all applications irrespective if they are in a datacenter, cloud, or delivered as SaaS, so you can resolve issues quickly.

Citrix solutions for single sign-on

Employees rely on a variety of applications to get work done, but managing access to them can be a big challenge. Citrix Secure Private Access provides adaptive authentication and SSO to all IT sanctioned apps in one place, with a single set of credentials for easy access to corporate resources. Security is improved with fewer passwords for users to manage, and employees can boost productivity with a unified digital workspace.

Additional resources