Engineering Questions with Answers - Multiple Choice Questions

# Atbash Cipher Multiple Choice MCQ

1 - Question

Which of the following cipher does not require a key for encrypting plain text?
a) atbash cipher
b) affine cipher
c) playfair cipher
d) vigenere cipher

Explanation: Out of the given options only atbash cipher does not require a key for encryption. Atbash cipher is an example of a substitution cipher.

2 - Question

Atbash cipher was originally used for encrypting _____________
a) english alphabet
b) greek alphabet
c) hebrew alphabet
d) hindi alphabet

Explanation: Atbash cipher was originally built to encrypt hebrew alphabet. But it can be used to encrypt any type of alphabets.

3 - Question

Which of the following cipher is a special case of affine cipher?
a) Vigenere cipher
b) Autokey cipher
c) Atbash cipher
d) Hill cipher

Explanation: Atbash cipher is a special case of affine cipher. We have to assume a=b=25 as the key in affine cipher to get the same encryption.

4 - Question

Choose the weakest cipher from the following?
a) vigenere cipher
b) rail fence cipher
c) hill cipher
d) atbash cipher

Explanation: Atbash cipher is the weakest cipher out of the given options. This is because it is a simple mono alphabetic substitution cipher with almost no security. It can be cracked without even knowing which technique has been used for encryption.

5 - Question

Which of the following is a mono alphabetic substitution cipher?
a) vigenere cipher
c) play fair cipher
d) atbash cipher

Explanation: Atbash cipher is the only mono alphabetic substitution cipher out of the given options. All the remaining options fall under the category of poly alphabetic cipher.

6 - Question

Atbash cipher is less secure than affine cipher.
a) True
b) False

Explanation: Affine cipher is more secure as compared to pigpen cipher. Atbash cipher is a special case of affine cipher and can be cracked without even knowing which technique has been used for encryption.

7 - Question

Atbash cipher is an example of?
a) Mono alphabetic substitution cipher
b) Transposition cipher
c) Poly alphabetic substitution cipher
d) Geometric substitution cipher

Explanation: Atbash cipher is an example of mono alphabetic substitution cipher. It replaces each alphabet of the plain text with a corresponding letter which we can see in the table below.

```A - Z	  J - Q	    S - H
B - Y	  K - P	    T - G
C - X	  L - O	    U - F
D - W	  M - N	    V - E
E - V	  N - M	    W - D
F - U	  O - L	    X - C
G - T	  P - K	    Y - B
H - S	  Q - J	    Z - A
I - R	  R - I```

8 - Question

Atbash cipher cannot be cracked until the exact type of encryption of ciphered text is known.
a) True
b) False

Explanation: Atbash cipher is a very weak cipher. It can be easily broken without even knowing the exact technique which has been used for encryption. We can just assume the ciphered text to be a substitution cipher in order to crack it.

9 - Question

What will be the ciphered text corresponding to plain text “SECRET” if atbash cipher is used for encryption?
a) VHIXVG
b) HVXIVG
c) HXVIVG
d) VIHXIV

Explanation: Atbash cipher replaces each alphabet of the plain text with a corresponding letter which we can see in the table below.

```A - Z	  J - Q	    S - H
B - Y	  K - P	    T - G
C - X	  L - O	    U - F
D - W	  M - N	    V - E
E - V	  N - M	    W - D
F - U	  O - L	    X - C
G - T	  P - K	    Y - B
H - S	  Q - J	    Z - A
I - R	  R - I```

So the ciphered text would be “HVXIVG”.

10 - Question

What will be the plain text corresponding to ciphered text “MAO” if atbash cipher is used for encryption?
a) NZL
b) IND
c) AUS
d) ENG

Explanation: Atbash cipher replaces each alphabet of the plain text with a corresponding letter which we can see in the table below.

```A - Z	  J - Q	    S - H
B - Y	  K - P	    T - G
C - X	  L - O	    U - F
D - W	  M - N	    V - E
E - V	  N - M	    W - D
F - U	  O - L	    X - C
G - T	  P - K	    Y - B
H - S	  Q - J	    Z - A
I - R     R - I```

So the plain text would be “NZL”.

11 - Question

Which of the following is not true about atbash cipher?
a) it is a mono alphabetic substitution cipher
b) it can only be used to encrypt hebrew alphabet
c) it is a special case of affine cipher
d) it is weaker than playfair cipher