What technology is likely to be deployed for a single sign-on system in cloud services?

OpenID is a protocol designed specifically for single sign-on (SSO) applications, primarily in scenarios involving web-based services. It allows users to authenticate once and gain access to multiple services without the need to log in separately to each one. This streamlining of credential usage across different platforms simplifies the user experience and reduces the password fatigue associated with managing multiple accounts.

While OAuth is a widely used framework for authorization, it is fundamentally different from OpenID, as it focuses on granting access to resources rather than identity verification. SAML, on the other hand, is also a popular choice for SSO, particularly in enterprise settings, as it facilitates secure exchanges of authentication and authorization data between parties. Kerberos is a network authentication protocol that is primarily used within internal systems and is less suited for cloud services that require flexible, cross-domain SSO capabilities like OpenID provides.

The suitability of OpenID for cloud services, as opposed to the other technologies, highlights its emphasis on web identity and its compatibility with various cloud applications, making it a likely candidate for deployment in single sign-on systems in that environment.