2.3

• Defensive Design


  Making sure no errors in the program-designing software with safeguards to prevent errors, failures or security vulnerabilities
• Authentication


  • To verify the identity of a user
  • Method of anticipating misuse - systems should anticipate that users will attempt to gain unauthorised access to accounts
• Factors

  Something you are, something you know, something you have
• Two Factor Authentication


  Two different authentication types are required to access a program
• Input Validation


  Ensures that data inputted is within specific bounds and meets criteria, to prevent unexpected behaviour/security risks
• Validation will not catch all errors as users may still make typos
• Verification


  • Requires the user to enter key info to reduce the risk of typos
• Input Validation Checks


  • Format check
  • Presence check
  • Length Check
  • Range check
• Maintainability


  Ease with which software can be modified, updated/expanded to meet changing requirements over time
• Maintainable Code


  • Organised, readable, scalable, shorter
  • Use of sub programs to independently isolate code and easy to debug
• Testing


  Helps to locate and remove errors, ensures the program works as it should
• Testing Types


  • Final Testing
  • Iterative Testing
• Final Testing


  • Can be harder to locate and fix errors at this stage due to the amount of code
• Iterative Testing


  • Constantly testing the program throughout the development process (individual lines/sections)
  • Easier to fix errors
• Test Data


  • Normal data
  • Boundary data
  • Invalid data
  • Erroneous data