Data Structure II Mock Test 9

10%

Question 1 of 10

1. Which cipher is represented by the following function?

public class Cipher
{
    public static String encrypt(String text, final String key)
    {
        String res = "";
        text = text.toUpperCase();
        for (int i = 0, j = 0; i < text.length(); i++)
        {
            char c = text.charAt(i);
            if (c < 'A' || c > 'Z')
                continue;
            res += (char) ((c + key.charAt(j) - 2 * 'A') % 26 + 'A');
            j = ++j % key.length();
        }
        return res;
    }

vigenere cipher

hill cipher

rotor cipher

keyword cipher

Question 1 of 10

Question 2 of 10

2. Which of the following is not a type of transposition cipher?

Rail fence cipher

Columnar transposition cipher

One time pad cipher

Route cipher

Question 2 of 10

Question 3 of 10

3. Which of the following is a difference between beaufort cipher and vigenere cipher?

they use the same table for encryption, but in a different manner

vigenere cipher is poly alphabetic whereas beaufort cipher is mono alphabetic

they use different tables for encryption

vigenere cipher uses a key whereas no key is required for using beaufort cipher

Question 3 of 10

Question 4 of 10

4. Poly alphabetic cipher harder to decipher than mono alphabetic cipher.

false

true

Question 4 of 10

Question 5 of 10

5. What is the rule for encryption in playfair cipher if the letters in a pair does not appear in same row or column?

that pair is neglected

they are replaced by the letter appearing immediately below them respectively

they are replaced by the letter appearing immediately right to them respectively

they are replaced by the letter of the same row at the corner of the rectangle defined by the original pair respectively

Question 5 of 10

Question 6 of 10

6. Which cipher is represented by the following function?

void Cipher(string msg, string key) 
{ 
	// Get key matrix from the key string 
	int keyMat[3][3]; 
	getKeyMatrix(key, keyMat); 
	int msgVector[3][1]; 	
	for (int i = 0; i <=2; i++) 
		msgVector[i][0] = (msg[i]) % 65; 
	int cipherMat[3][1]; 
	// Following function generates 
	// the encrypted vector 
	encrypt(cipherMat, keyMat, msgVector); 
	string CipherText; 	
	for (int i = 0; i <=2; i++) 
		CipherText += cipherMat[i][0] + 65; 	
	cout  << CipherText; 
}

hill cipher

keyword cipher

rotor cipher

vigenere cipher

Question 6 of 10

Question 7 of 10

7. Route cipher is closely related to?

Autokey cipher

Hill cipher

Rail fence cipher

Columnar transposition cipher

Question 7 of 10

Question 8 of 10

8. Trithemius cipher is harder to crack than vigenere cipher.

true

false

Question 8 of 10

Question 9 of 10

9. Which of the following is a type of substitution cipher?

transposition cipher

transforming cipher

Mono alphabetic cipher

transportation cipher

Question 9 of 10

Question 10 of 10

10. Consider the expression T & F | T. What is the number of ways in which the expression can be parenthesized so that the output is T (true)?

Question 10 of 10