# MCQ | Cryptography Ciphers (Level: Easy) | Set 2

Here, we have a set of multiple-choice questions and answers (quiz) on ciphers in Cryptography (basic concepts of Cryptography Techniques and different types of ciphers).
Submitted by Monika Sharma, on February 02, 2020

1) You are supposed to use hill cipher for encryption technique. You are provided with the following matrix,

```    A   =   [   4  2
2  1 ]
```

Is the given matrix 'A', a valid key to be used for encryption?

1. Yes
2. No
3. Can't be determined
4. Data insufficient

Explanation:

For choosing any square matrix as a key, it should be taken care that the matrix is invertible, i.e. its inverse must exist. Here, in this case,

```    | A | = 0
```

Therefore, it means that 'A' is not an invertible matrix. Hence matrix 'A' cannot be chosen as a key matrix for encryption in the Hill cipher.

2) The DES (Data Encryption Standard) cipher follows the fiestal structure. Which of the following properties are not shown by the fiestal structure?

1. The input text is divided into two parts: one being left half and another one being right half.
2. Swapping of the left and right halves are performed after each round.
3. The plain text is converted into a matrix form first
4. None of the above

Answer: c) The plain text is converted into a matrix form first

Explanation:

The fiestal structure does not require the conversion of the plain text into matrix form at any of its steps.

3) Among the following given options, chose the strongest encryption technique?

1. DES ( Data Encryption Standard)
2. Double DES
3. Triple DES

Explanation:

It has been proved that the AES performs much better than the all the other DES, whether it be single DES or series of DES.

4) What is the full-form of RSA in the RSA encryption technique?

1. Round Security Algorithm
4. None of the above

Explanation:

The RSA algorithm was named after the three scientists who developed this technique and the name RSA is itself the abbreviation of their names: Rivest, Shamir, and Adleman.

5) Consider the following steps,

1. Substitution bytes
2. Shift Rows
3. Mix columns

The above steps are performed in each round of which of the following ciphers?

1. Rail fence cipher
2. Data Encryption Standard (DES)
4. None of the above

Explanation:

Each round of AES includes the mentioned steps.

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