The latest NIST (United States National Institute for Standards and Technology) guidelines on password policies recommend a minimum of 8 characters. Perhaps more interesting is what they recommend against. They recommend against allowing password hints, requiring the password to contain certain characters (like numeric digits or upper-case characters), using knowledge-based authentication (e.g., what is your mother's maiden name?), using SMS (Short Message Service) for two-factor authentication, or expiring passwords after some amount of time. They also provide recommendations on how password data should be stored.
[Ed. Note: Contrary to common practice, I would advocate reading the entire linked article so we can have an informed discussion on the many recommendations in the proposal. What has been your experience with password policies? Do the recommendations rectify problems you have seen? Is it reasonable to expect average users to follow the recommendations? What have they left out?]
(Score: 1, Insightful) by Anonymous Coward on Friday August 19 2016, @10:00PM
^^^This! And if the site has a policy where you have to change your password frequently, you will NEVER be able to come up with a secure password that you can remember. Thus, you will rely on the password recovery mechanism with its attendant weaker security. FAIL! Let people come up with a good password and keep it. If your system is compromised, the attackers will have wallked off with your data before the password change policy kicks in anyway! Security theater, I tell you.