Valid system passwords
System passwords must be at least 8 characters long and include at least two of the following four different character classes:
- Lower case letters (abc)
- Upper case letters (ABC)
- Numbers (123)
- Special characters (!"#)
Also, the password must not be based on a dictionary word and it has to be different than your previous password to a certain extent.
All passwords given to you by services or admins should be changed immediately after the first login.
Don't let anyone know your password for Blinkenshell. Don't write it down at places where others might be able to view it, especially not on your computer (a paper note in your wallet might be a good idea.)
It's highly recommended to not use the same password for different services (especially important to not use the same password over non-encrypted protocols like IRC.)
And lastly, change your password as soon as possible (use the command kpasswd) if you suspect that somebody else might have gotten their hands on it.