UK intelligence and the Communications-Electronics Security Group (CESG), which is part of the security organization GCHQ, has advised those using a computer to ignore previous advice every couple of months.
“The problem is that this doesn’t take into account the inconvenience to users - the ‘usability costs’ - of forcing users to frequently change their passwords. The majority of password policies force us to use passwords that we find hard to remember,” CESG said on its website.
If a person is constantly changing their password, the chances are that it will be written down because of the difficulty in remembering it. However, this makes an account vulnerable to being unlawfully entered should the password fall into the wrong hands.