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Users tend to choose easier to remember passwords. System-generated passwords can provide stronger, harder to guess passwords. Since they are based on rules provided by the administrator, they can include combinations of uppercase/lowercase letters, numbers and special characters, making them less vulnerable to brute force and dictionary attacks. One danger is that they are also harder to remember for users, who will tend to write them down, making them more vulnerable to anyone having access to the user`s desk. Another danger with system-generated passwords is that if the password-generating algorithm gets to be known, the entire system is in jeopardy. Source: RUSSEL, Deborah & GANGEMI, G.T. Sr., Computer Security Basics, O`Reilly, July 1992 (page 64).