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cryptography practise

Total questions: 20

Worksheet time: 28mins

Name
Class
Date
1.
For Modular Arithmetic what value is the most important?
a)
The Modulo
b)
The Given Number
c)
The Remainder
d)
The Divisor
2.
What is 7 mod 3?
a)
1 mod 3
b)
2 mod 3
c)
3 mod 3
d)
0 mod 3
3.
What is 57 mod 7?
a)
0 mod 7
b)
1 mod 7
c)
7 mod 7
d)
-1 mod 7
4.
What is 99 mod 100?
a)
99 mod 100
b)
100 mod 99
c)
1 mod 100
d)
100 mod 1
5.
What does 36 mod 13 look like using the Quotient Remainder Theorem?
a)
36 = 13 * 2 + 10
b)
36 = 10 * 3 + 6
c)
13 = 36 * 1 - 23
d)
6 = 36  - 10 * 3
6.
What does 13 mod 126 look like using the Quotient Remainder Theorem?
a)
13 = 126 * 0 + 13
b)
126 = 13 * 9 + 9
c)
13 =  126 * 0 + 13
d)
13 = 126 + 13 
7.
What is 9 mod 2 - 10 mod 2 congruent to?
a)
0 mod 2
b)
1 mod 2
c)
-1 mod 2
d)
-2 mod 2
8.
What is 6 mod 9 + 11 mod 9 congruent to?
a)
8 mod 9
b)
6 mod 9
c)
7 mod 9
d)
0 mod 9
9.
what is (-5 mod 4) - (-3 mod 4) congruent to?
a)
2 mod 4
b)
1 mod 4
c)
-2 mod 4
d)
-1 mod 4
10.
What is 14 mod 8 - 15 mod 8 congruent to?
a)
7 mod 8
b)
1 mod 8
c)
0 mod 8
d)
6 mod 8
11.

In Cryptography, original message, before being transformed, is called

a)

Simple Text

b)

Plain Text

c)

Cipher Text

d)

Filled Text

12.

An encryption algorithm transforms plain text into:

a)

Cipher text

b)

Simple Text

c)

Empty Text

d)

Plain Text

13.

_______ is the science and art of transforming messages to make them secure and immune to attacks.

a)

Cryptography

b)

Cryptoanalysis

c)

neither Cryptography nor Cryptoanalysis

d)

either Cryptography or Cryptoanalysis

14.

A(n) ______ algorithm transforms cipher text to plain text.

a)

Encryption

b)

Decryption

15.

The _______ is a number or a set of numbers on which the cipher operates.

a)

secret

b)

cipher

c)

key

d)

none of the mentioned

16.

The art and science of breaking the cipher text is known as

a)

Cryptanalysis

b)

Cryptography

c)

Staganography

d)

Watermarking

17.

A method for determining a solution to a problem by sequentially testing all possible solutions.

a)

brute force

b)

relative frequency

c)

cipher

d)

paired keys

18.

The process of converting a ciphertext into plaintext.

a)

encryption

b)

decryption

c)

plaintext

d)

cryptography

19.

What is the term used to describe the science of making and breaking secret codes?

a)

cryptology

b)

impersonation

c)

spoofing

d)

factorization

e)

jamming

20.

A cipher is _________________________.

a)

a person who makes up secret codes

b)

an algorithm that is used to scramble text so that it can be passed in secret

c)

a lock that can be used to lock a message in a lock box

d)

any puzzle, such as a crossword or Sudoku puzzle