CompTIA Security+ All-in-One Exam Guide (Exam SY0-301), 3rd Edition, 3rd Edition

Single Sign-On

To use a system, users must be able to access it, which they usually do by supplying their user IDs and corresponding passwords. As any security administrator knows, the more systems a particular user has access to, the more passwords that user must have and remember. The natural tendency for users is to select passwords that are easy to remember, or even the same password for use on the multiple systems they access. Invariably, users will forget the passwords they chose for infrequently accessed systems, which creates more work for system administrators who must assist users with password changes or password recovery efforts. Wouldn’t it be easier for the user simply to log in once and have to remember only a single, good password? ...