Passwords and Security

Passwords are readily in use throughout most parts of our lives now. They are designed to authenticate a user’s access to an area, and restrict other users, but this makes passwords a target for those without authorisation.

What is a Computer Password?

A password is a string of characters used to authorise access to information or a computer. Passphrases are similar to passwords, but are are typically longer than passwords and contain multiple words that create a phrase. This provides added security. 

When you create a password or passphrase, you should make it strong, which means it’s difficult to guess or crack (break the password). It’s a good idea to use strong passwords on all user accounts on your computer. Computers at work often form part of a network, the network administrator may determine the minimum requirements for a password to ensure that it cannot be broken easily.

What makes a password or passphrase strong?

Strong passwords and passphrases can be made stronger by

• Increasing the length,.
  Say for example you use the letters of the alphabet to create your password, that is 26 possible letters, so for a single letter password there are 26 alternatives (a to z). So now set a criteria that uses 2 letters (aa – zz) that is a possible 26 x 26 (or 26² = 676) alternatives. So if we were now to say that there had to be 8 characters that would give 26⁸ (=208827064576) alternatives, much more difficult to break.
• Strong passwords and passphrases contain characters from different categories:
  By using a wider number of characters the number of alternatives can be increased further –
  Lowercase letters – a, b, c… (26 characters),
  Now add Uppercase letters – A, B, C … (an additional 26 characters, 52 in total)
  Then add Numbers – 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 (an additional 10 characters, 62 in total)
  and finally some systems allow the use of symbols found on the keyboard (all keyboard characters not defined as letters or numerals) and spaces ` ~ ! @ # $ % ^ & * ( ) _ – + = { } [ ] \ | : ; " ‘ < > , . ? /
  Using letters and numbers for an 8 character password now allows for 62⁸ (218340105584896) possible alternatives. Mixing letters and numbers makes a password more difficult to guess and crack.

A password can still meet all the criteria or a strong password, but still be weak, for example, Hello2U! meets the criteria for a strong password, it contains uppercase letters, lowercase letters, numbers and symbols , but is still weak because it contains a complete word “Hello”. He110 2 U! is a stronger alternative because it replaces some of the letters in the complete word with numbers and also includes spaces.

Windows passwords can be much longer than 8 characters, Windows allows for passwords up to 127 characters long. However, if you are on a network that also has computers running Windows 95 or Windows 98, consider using a password that is no longer than 14 characters. If your password is longer than 14 characters, you might not be able to log on to your network from computers running those operating systems.

Passwords are used to retain security, keep it safe.