What is Single Sign On and How does SSO Work?

What is Single Sign On?

Single sign on (SSO) is an authentication scheme that helps users sign in to multiple applications through a single username and password. This technology exercises one set of credentials to access different websites and apps. Have you ever noticed while logging into an account or third party website, an option to log in with Facebook or log in with Google is available? The moment you choose any of these methods, you magically enter the application or website. The question is, how this happens? Well! There is no magic but SSO. SSO is a session and user authentication service that aids users to conveniently log in with a single set of credentials (username and password) to access each software system.

Many small, large, or medium sized organizations and enterprises’ IT teams use this technology to access and manage multiple applications. Even remote workers can benefit from this practice for their SaaS applications.

what is single sign on

Every application, such as Microsoft Office 365, Webex Meetings, Salesforce, and many more, require users to fill in the credentials to enter the applications. Now, let’s imagine if you have signed up or registered every other application with a different username and password, how difficult it might get to remember the details. Secondly, the chances of misuse or hacking your accounts are high. There is when SSO comes into the picture. This authentication scheme helps users to establish their identity once and access different applications at ease. You no longer have to create an identity over and over again for multiple software systems.

SSO is a crucial feature for each application that provides IAM or access control solutions. IAM solutions perform users’ digital identities check and permit access to only registered users. Implement the SSO technology for your organization and reap the benefits, gain more productivity, and enjoy a more secure authentication.

How Does SSO Work?

what is sso

Every time a user creates an account, their identity is saved in the form of an authentication token that comprises the user’s email address or a username. This token is nothing but bits of information about the user stored in their browser or SSO’s servers. It is more like the user is issued an identity card that needs to be checked with the SSO every time you try to access an app. Once the SSO service verifies the user’s authentication token, they have the authority to enter any application. However, if the user has not registered, they will need to perform the action through the SSO service. There are many benefits of using SSO login, including better administrative control, network security, improved user productivity, reduced IT costs, time saving, reduces password fatigue.

SSO service is not responsible for storing any user’s identity. The process to maintain the user’s database is performed by an Identity Management service provider. These are the ones who store users’ information, check the credentials and approve whether the user has any database or not. SSO’s job is to confirm whether the shared user’s login credentials are similar to the database entries. But, the catch is they are not the ones who manage these database entries. It’s like you visit a book store and request the librarian to help you fetch a book. Now, the librarian will check the book titles and confirm their availability. The bookkeepers do not have everything memorized but can easily access the requested book on someone else’s behalf.

This complete SSO process works based on trust between the Application (Service provider) and the SSO system (Identity Provider). The two sources exchange a certificate with a piece of signed identity information to be sure that it is coming from a trusted source or platform. It usually works this way:

  • A user visits the application or website (Service provider) to get access.
  • The application creates a token with the user’s email address to the SSO system (Identity Provider). By sending the authentication token, the user requests to verify the credentials.
  • Firstly, the Identity Provider checks if any user exists with the shared ID. If yes, follow step 5.
  • If there is no data found, users will need to generate credentials with the help of username, password, or One Time Password authentication.
  • As the credentials are verified, another token by the Identity provider is forwarded to Service Provider, confirming the authentication success.
  • Later, as the Service provider receives the validation passed by the user’s browser, the user is granted access to enter the application.

Another example is if you have a WordPress website and want to implement WordPress SSO for your users using Azure AD as the identity provider, you can setup WordPress to authenticate users with Single Sign On using your Azure Active Directory.

Pros of Using an SSO Login

Apart from being an easy to use and simple technology, SSO has many more benefits. Have a look at some of the advantages SSO possess:

Make strong passwords: SSO helps create one password for all platforms. It is a better strategy to keep one password and remember it for multiple applications rather than registering accounts with different passwords. The only thing you need to ensure is that you are using a strong password.

Now, what makes a password strong and difficult for anyone to crack? Use Capital letters, numbers, and special character combinations to create a strong password. For example, W#2jfsi12478@124.

Avoid Repeating Passwords: People often create different passwords for each application for safety purposes. But, unaware they often reuse these passwords, which might enhance the chances of high security risk. Just keep in mind if the password database gets compromised, you may face repercussions. Attackers may use this information to track other applications and services as well. To eliminate this issue, the SSO concept (OneLogin) got introduced.

Password Policy Enforcement: Knowing SSO allows one place to generate passwords, it has enforced strict password security rules. For instance, to keep data safe from hackers or attackers many companies demand periodically reset their passwords. With SSO, things get much easy to manage as the user needs to reset only one password.

Provides Multi factor authentication: This scheme also requires more than one identity factor to authenticate or login into an application. For example, apart from a username or password, you might require to enter a One Time Password (OTP) for authentication.

No external storage: Mostly applications and services store user passwords in an unmanaged manner with fewer security practices. However, in SSO, this information is stored internally under the supervision of IT experts.

No Need to Spend Extra Time on Password Recovery: IT experts or users do not require signing in to each app or website to reset passwords with SSO. If you are not practicing SSO, then as an IT expert, you might need to log in to every app to perform this job function. But, with SSO, the chances are high that you waste less time in recovering your password. Thus, your team can focus on other essential areas to provide improved business continuity and productivity.

What Challenges SSO Login Users May Face?

  • If attackers crack your strong passwords, you may lose risk all your apps and data altogether. Since all apps will log in through the same credentials, there are high chances that the attacker may log in to your multiple applications and websites.
  • If due to any internal issue SSO breakdowns, then all your connected apps and websites will stop. That is why people look for other plans as well to manage their applications in case of a breakdown.
  • It might take a user more time to set up SSO in some cases as each environment varies. So, in few cases, it may take longer to connect the internet provider to the service provider.
  • A user may require additional authentication servers with Reduced sign on (RSO) to accommodate multiple access.
  • There are a few applications and websites that allow cookies and sharing user data to additional third party entities. One needs to be really careful in this section with SSO linked sites.


Enabling single sign on can save your time and improve security. It is one of the leading technologies practiced by a large population to access their applications faster. Instead of keeping track of multiple sets of credentials, this scheme simplifies the management of usernames and passwords. Both users and administrators can avoid wasting time on password reset and recoveries, can centrally control the device, encompass the benefit of multi factor authentication (MFA).

SSO involves the use of one set of credentials to access and manage multiple websites and applications. OpenID Connect (authentication layer), Security Access Markup Language (Open standard), OAuth 2.0 (framework) are a few terms that are involved in providing Single Sign on functionality. It also has a few drawbacks. For example, losing access to all applications at once is high. With SSO, you have to no longer waste your time logging in again and again to access or manage all company approved applications, including both the application on cloud or on premises. Yet, it is one of the best techniques an IT expert must prefer for their organization as it is highly secure in many terms.
Google, Twitter, LinkedIn, and Facebook are a few social platforms that offer popular SSO services. These platforms permit signing in to other applications and websites through social media authentication credentials. Social single Sign On is also a convenient practice with better security options.

Avatar for Hitesh Jethva
Hitesh Jethva

I am a fan of open source technology and have more than 10 years of experience working with Linux and Open Source technologies. I am one of the Linux technical writers for Cloud Infrastructure Services.

0 0 votes
Article Rating
Notify of
Inline Feedbacks
View all comments
Would love your thoughts, please comment.x