Answer Happy

Question 1 Open TMA Q1.fprg with Flowgorithm, and examine the flowchart for Vigenere Cipher, a symmetric encryption, (https://en.wikipedia.org/wiki/Vigen%C3%A8re_cipher). A pictorial representation of symmetric key encryption is shown in Figure QI.1. Symmetric key encryption uses the same secret key to encrypt and decrypt a message: The sender uses a secret key to encrypt a plain text (the message) into cipher text (scrambled text that is intelligible). . The recipient uses the same secret key to decrypt the scrambled text to plain text. Symmetric Encryption Sam Kay Secret Ene AASHLO TOR/>881 RO6/12-11 SPR39020 D ecryption Plain Text Cipher Text Plain Text Figure. O1.1 Symmetric Encryption Study the flowchart, and execute it via the slow run button on Flowgorthm. Add breakpoints to allow you to observe the values of the variables at various points of the flowchart. (a) Explain and describe the purposes, input, output, and logic of each module in the flowchart: (1) IntToArray (2 marks) (ii) EncryptPhoneNumber (3 marks) (iii) DecryptPhoneNumber (3 marks) (b) Make postings to the Lecture Group Discussion Forum to discuss with fellow students to clarify your doubts and to explain your understanding. Then derive your own solution to parts (i) and (ii), and justify your solution using relevant postings which you agree or disagree. Failure to justify using your postings and others' postings will incur a penalty. Secret Key ncryption

EncryptPhoneNumber ● assumes input values adhere to these restrictions: The message is an 8 digit Singapore phone number. The key is 5 digits. . Is it possible that some input cause an error even if the input values adhere to the TWO (2) restrictions? Justify your answer. If it is possible that some input can cause an error, either modify the flowchart or the program obtained using the automatic conversion tool provided by Flowgorithm, to avoid the error. (6 marks) (ii) Convert the flowchart into a Python program using the automatic conversion tool provided by Flowgorithm. Modify the program to use the datatype str instead of int to store the key, phone number and scrambled phone number. (5 marks) (c) Github is a rich resource for source codes. Review the programs for Vigenere Cipher found in the following two URLs: ● https://github.com/JB1984/Vigenere/blob ... igenere.py https://github.com/nazaninsbr/Vigenere-Cipher- Implementation/blob/master/main.py Make postings to the Lecture Group Discussion Forum to discuss with fellow students to clarify your doubts and to explain your understanding of the TWO (2) programs. Then derive your own solution to parts (i) and (ii) using relevant postings which you agree or disagree. Failure to justify using your postings and others' postings will incur a penalty. (i) Compare and contrast the TWO (2) programs, and describe their strengths and weaknesses. Justify your answer. (4 marks) (ii) Employ structured programing principles to consolidate the TWO (2) programs into one program to avoid their weaknesses, based on your discussion in Q1(c)(i). (7 marks) (i)