administrator to change a user’s privileges and know that the results will propagate network wide. Improved user productivity. Users are no longer bogged down by multiple logons, nor are they required to remember multiple passwords in order to access network resources. This is also a benefit to Help desk personnel, who need to field fewer requests for forgotten passwords. Better network security. Eliminating multiple passwords also reduces a common source of security breaches—users writing down their passwords. Finally, because of the consolidation of network management information, the administrator can know with certainty that when he disables a user’s account, the account is fully disabled. Consolidation of heterogeneous networks. By joining disparate networks, administrative efforts can be consolidated, ensuring that administrative best practices and corporate security policies are being consistently enforced. 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. Criticism 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