Defensive Design

• What is the focus of Key Stage 3 and GCSE in this document?

  Fundamentals of IT and programming
• What is the purpose of defensive design in programming?

  To create secure and robust programs
• What is one consideration in defensive design?

  Anticipating misuse
• How does anticipating misuse help in programming?

  It prevents potential misuse of the app
• What is input sanitisation?

  Cleaning up input data
• Why is input sanitisation important?

  It prevents SQL injection attacks
• What does validation check in programming?

  Whether input data meets criteria
• What is an example of validation?

  A length check on a password
• What is verification in programming?


  Checking if entered data is correct
• What is an example of verification?

  Double entry of data
• What is authentication in programming?

  Ensuring authorized user access
• What is an example of authentication?

  Usernames and strong passwords
• What is maintainable code?

  Code that is easy to read and understand
• Why is maintainable code important?

  It allows easy understanding by others
• What are the key aspects of input validation?

  • Range Check: Data within a range
  • Type Check: Data of a certain type
  • Format Check: Data in a specific format
  • Presence Check: Data not left blank
  • Lookup Table: Acceptable entries list
  • Length Check: Input length within limits
• What is a range check?

  Checks if data is within a range
• What is a type check?

  Checks if data is a certain type
• What is a format check?


  Checks data is entered in a certain way
• What is an example of a format check?

  Date of Birth (DD/MM/YYYY)
• What is a presence check?

  Checks that data has been entered
• What is an example of a presence check?

  Password: fluffythecat123
• What is a lookup table?

  A table of acceptable entries
• What is an example of a lookup table?

  A list of acceptable entries
• What is a length check?

  Checks the length of the input
• What is an example of a length check?

  Telephone Number: 08323877319
• What are the methods to improve program maintainability?

  • Use subprograms for code reuse
  • Appropriate variable naming conventions
  • Indentation for readability
  • Comments for understanding code purpose
  • Use constants for consistency
• What is modularisation in programming?

  Using subprograms to reuse code
• Why is using appropriate variable names important?

  It ensures the purpose is understood
• What is the purpose of indentation in code?

  To improve readability of code
• Why are comments crucial in programming?

  They help understand code purpose
• What is the benefit of using constants in programming?

  Improves code consistency
• How does using constants help in debugging?

  It makes code easier to read
• What are the exam questions related to defensive design?

  1. Describe considerations for defensive design.
  2. Describe each validation check with examples.
  3. Explain ways a program can be maintained.