When individuals have accounts on multiple systems and use the same authenticators such as passwords, there is the risk that a compromise of one account may lead to the compromise of other accounts. Alternative approaches include having different authenticators (passwords) on all systems, employing a single sign-on or federation mechanism, or using some form of one-time passwords on all systems. Organizations can also use rules of behavior (see PL-4) and access agreements (see PS-6) to mitigate the risk of multiple system accounts.