Chapter 15, Problem 4PC

Program Plan Intro

Flexible Encryption

Program Plan:

• Include the required header files to the program.
• Define “Encryption” class.
  • In public, create a constructor, destructor and pure virtual function.
  • In protected, declare the required variable.
• Define the constructor.
  • Open the input file and output file.
  • If the input file is not present, exit the program.
  • If the output file is not present, exit the program.
• Define the destructor.
  • Close the input and output file.
• Define the subclass “encrypt” function.
  • Declare the required variables.
  • Read the input file and write the encrypted form to the output file.
• Define the “Encryption” function.
  • In public, define the “transform” function.
    • Return the encrypted value.
• Define the “main()” function.
  • Declare the required variables.
  • Get the input and output file name from the user.
  • Create the objects for the classes.
  • Get the encryption key from the user.
  • Call the function “setKey” function with the key value.