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What is Single Sign On (SSO)? Definition, characteristics and advantages

Over time we continue to use more systems in our everyday lives, and memorising the complex passwords for each of those systems is a challenge. Single Sign On (SSO) may be the solution to this issue. Using it, we are able to access different applications and services with a single identity, and adding and deleting users in our systems will be easier.

What is Single Sign On (SSO), and what does it do?

Single Sign On, also known as SSO, allows users to have access to multiple applications by signing in using only one existing account. SSO is most useful when there are multiple systems that can be accessed using a password, and we want to prevent repeated authentication to them each time the user is disconnected from a given service. This is highly convenient for users, since, by identifying themselves just once, it is possible to maintain a valid session for the rest of the applications which use SSO.

SSO aims to simplify the user experience on the Internet by completely facilitating session sign-in tasks.

Using the Single Sign On identification system, it is possible to have multiple accesses with a single account; for example, by signing in to Gmail we will have account level access to its various web applications, such as Google Docs, Google Maps, Google Books, etc.

Single Sign On (SSO) Features

This authentication procedure facilitates access to different platforms. It also has other important features in regards to simple management, security, ease of use and seamlessness.

Easy management

Using SSO synchronises passwords and user information, which makes access to different platforms and resources easier.


This authentication system improves network and application security. Single Sign On can uniquely identify a user, and ensure compliance with the most demanding security standards.

Information provided by SSO is encrypted and transmitted across the network.

Ease of use

SSO solutions improve the user experience by avoiding the interruptions caused by password requests to access their essential IT tools.

The user is authenticated once and the system allows them to access the resources for which they are authorised.


Access to all applications takes place seamlessly due to sign-in automation.

Types of Single Sign On (SSO) Authentication

Enterprise Single Sign On (E-SSO)

This type of system works as a primary authentication, intercepting login requests when required by secondary applications in order to fill out the user and password fields. The E-SSO system allows for interaction with other systems that may disable the login screen.

Web single sign-on (Web-SSO)

This type of solution only works with applications which can be accessed through the web, and its goal is the authentication of a user on several applications without the need to get identified again.

Access data is intercepted by a proxy server that performs the communication and then transfers the result to the computer that requested it. Unidentified users are redirected to an authentication service, returning a successful login.

Federated identity

This type of Single Sign On involves an identity management solution that uses established standards to enable applications to identify clients without the need for redundant authentication.

Open ID

Open ID is a decentralised SSO process in which the user identity is stored at a URL that any server can verify.

Single Sign On (SSO) Advantages and Disadvantages 



Streamlines user access to their applications Using a single password increases the chances of password vulnerability
Reduces the load of memorising several passwords When SSO fails, access to all related systems is lost
Easy to implement and connect to new data sources Identity spoofing in user external accesses

For businesses, having an authentication system such as Single Sign On means freeing the user of the burden of remembering several passwords, and also offers significant benefits directly related to efficiency and security. This also reduces calls to technical support or the IT department to solve issues related to password security.