Defensive design

Defensive design

1. Protection

   • Input sanitisation - Removing any unwanted character sbefore passing data through the program
   • Input validation - Checking if data meets certain criteria before passing it into the program.
     • This is often done via whitelisting and blacklisting.
       • Whitelisting - A list of data that the program accepts as valid - Any data that isn't this will be rejected
       • Blacklisting - A list of data that the program should reject - Any data that isn't on the blacklist will be accepted

2. Authentication

   • Authentication confirms the identity of a user before they can access pieces of data or features of the program.
     • This can be done with passwords
     • This can also be done with a passcode or security questions
     • There is ways to strengthen security
       • Force users to use strong passwords, and have them change it regularly.
       • Limit the number of failed password attempts before that account is unable to be accessed.

3. Key words

   • Machine code - Code that computers can read an example is binary
   • Assembly language - A language that assemblers use to turn high-level code into machine code.
   • High level languages - Code that humans can easily read and write - E.g. Python and Java
   • Low-level languages - Code that machines can read but humans cannot - E.g. machine code