Defensive Design

Defensive Design

1. Defensive Design helps to ensure programs function properly

   • When programs are functioning correctly they should never break and never produce errors.
   • In practice this is difficult to achieve - even the biggest software companies need to update and patch their programs regularly.

2. Programmers try to protect their programs through defensive design - they will try to:

   • Anticipate how users might misuse their program, then attempt to prevent it from happening.
   • Ensure their code is well maintained
   • Reduce the number of errors in the code through testing.

3. Make sure the Inputs can't be Exploited

   • The easiest way for a user to accidentally of intentionally misuse a program is when entering data.
   • There are two ways thatyou can prevent users from entering something you don't want them to:
     • Input Sanitisation: removing any unwanted characters before passing data through the program