SDR – What is Single Sign On – SSO

This is an article to inform the CEG Support Agent regarding the SSO that is being used by YES.

Single sign-on (SSO) is a property of access control of multiple related, but independent software systems. With this property a user logs in with a single ID and password to gain access to a connected system or systems without using different usernames or passwords, or in some configurations seamlessly sign on at each system.

Using the Lightweight Directory Access Protocol (LDAP) and stored LDAP databases on (directory) servers. A simple version of single sign-on can be achieved over IP networks using cookies but only if the sites share a common DNS parent domain.

Benefits of using single sign-on include:

  • Mitigate risk for access to 3rd-party sites (user passwords not stored or managed externally)
  • Reducing password fatigue from different user name and password combinations
  • Reducing time spent re-entering passwords for the same identity
  • Reducing IT costs due to lower number of IT help desk calls about passwords

SSO shares centralized authentication servers that all other applications and systems use for authentication purposes and combines this with techniques to ensure that users do not have to actively enter their credentials more than once.

Criticisms:

The term reduced sign-on (RSO) has been used by some to reflect the fact that single sign-on is impractical in addressing the need for different levels of secure access in the enterprise, and as such more than one authentication server may be necessary.

As single sign-on provides access to many resources once the user is initially authenticated (“keys to the castle”) it increases the negative impact in case the credentials are available to other people and misused. Therefore, single sign-on requires an increased focus on the protection of the user credentials, and should ideally be combined with strong authentication methods like smart cards and one-time password tokens.

Single sign-on also makes the authentication systems highly critical; a loss of their availability can result in denial of access to all systems unified under the SSO. SSO can be configured with session failover capabilities in order to maintain the system operation. Nonetheless, the risk of system failure may make single sign-on undesirable for systems to which access must be guaranteed at all times, such as security or plant-floor systems.

Furthermore, the use of single sign-on techniques utilizing social networking services such as Facebook may render third party websites unusable within libraries, schools, or workplaces that block social media sites for productivity reasons. It can also cause difficulties in countries with active censorship regimes, such as China and its “Golden Shield Project,” where the third party website may not be actively censored, but is effectively blocked if a user’s social login is blocked.

Security:

Software as a service (SaaS; pronounced /sæs/) is a software licensing and delivery model in which software is licensed on a subscription basis and is centrally hosted. It is sometimes referred to as “on-demand software”. SaaS is typically accessed by users using a thin client via a web browser.