What technology allows a user to log in once and access multiple systems without further authentication?

Single Sign-On (SSO) is a user authentication process that allows a user to log in once and gain access to multiple systems or applications without the need for re-entering credentials. This technology significantly enhances user convenience by reducing the number of times they need to log in, which can improve productivity and user experience, especially in environments where multiple applications are in use.

With SSO, once a user authenticates themselves to the centralized system, they are issued a token or session that is used to authenticate them to other systems or services without further authentication prompts. This mechanism relies on a trust established between the different systems involved, allowing seamless access.

Token-based 2FA, while it enhances security in the authentication process by requiring two forms of identity verification, does not provide the single sign-on functionality. RSA refers to a public-key cryptography algorithm often used in securing data, but it is not an authentication method that allows for SSO. Nondiscretionary is not a recognized term in the context of authentication technologies. Therefore, the seamless accessibility provided by SSO makes it the appropriate choice for users looking to simplify their login processes across multiple platforms.