wayground logo

Free Printable Worksheets

NEW

Font size

S
M
L
XL
Worksheets

Computer security Grade 7

Total questions: 36

Worksheet time: 36mins

Name
Class
Date
1.

Who was the first know user of the Caesar Cipher?

a)

Caesar Romanus

b)

Julius Caesar

c)

Alan Turing

d)

There isn't one

2.
What machine was used during WWII to encrypt and decrypt German messages?
a)
Enigma
b)
Atbash
c)
Secret
d)
Puzzler
3.

What was the name of the man who led the team that cracked the German's "Enigma Code" in WW2?

a)

Tim Berners-Lee

b)

Alan Turing

c)

Stephen Hawking

d)

Bill Gates

4.

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

a)

Simple Text

b)

Plain Text

c)

Cipher Text

d)

Filled Text

5.

An encryption algorithm transforms plain text into:

a)

Cipher text

b)

Simple Text

c)

Empty Text

d)

Plain Text

6.

_______ 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

7.

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

a)

Encryption

b)

Decryption

8.

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

9.

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

a)

Cryptanalysis

b)

Cryptography

c)

Staganography

d)

Watermarking

10.
What is encryption?
a)
When you put data / text into code making it difficult to read or understand.
b)
A secret or disguised way of writing; a code.
c)
A formal language designed to communicate instructions to a machine
d)
What is put in, taken in, or operated on by any process or system.
11.

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

12.

The process of converting a ciphertext into plaintext.

a)

encryption

b)

decryption

c)

plaintext

d)

cryptography

13.

Plaintext

a)

original message

b)

coded message

c)

algorithm for transforming plaintext to ciphertext

d)

info used in cipher known only to sender/receiver

14.

ciphertext

a)

•field of both cryptography and cryptanalysis

b)

•study of encryption principles/methods

c)

•converting plaintext to ciphertext

d)

•coded message

15.

cryptanalysis

a)

field of both cryptography and cryptanalysis

b)

study of encryption principles/methods

c)

•study of principles/methods of deciphering ciphertext without knowing key

d)

converting plaintext to ciphertext

16.

An encryption algorithm transforms plain text into:

a)

Cipher text

b)

Simple Text

c)

Empty Text

d)

Plain Text

17.

Encrypt the word alphabet using a Caesar cipher with a shift of 3

a)

DOSKDEHV

b)

DOSKDEHU

c)

DOSKDEHW

d)

DOSKDEHX

18.

The following word was encrypted using a Caesar cipher with a shift of 2: ecguct. What word is it?

a)

julius

b)

caesar

c)

romans

d)

cipher

19.

What encryption algorithm uses the same pre-shared key to encrypt and decrypt data?

a)

hash

b)

one-time pad

c)

symmetric

d)

asymmetric

20.

The two methods of encrypting data are?

a)

Substitution and transposition

b)

Block and stream

c)

Symmetric and asymmetric

d)

DES and AES

21.

"CIPHERTEXT" has been encrypted with Caesar cipher to "EKRJGTVGZV". The key used was:

a)

7

b)

6

c)

3

d)

2

22.
If you were to use a caeser cipher with a key of 3 shifts to the left, how would you encrypt the word: Cipher?
a)
ZAMEBO
b)
ZOMEBO
c)
ZFMEBO
d)
ZFMEBA
23.

Cryptography is the science of encrypting or hiding information.

a)

True

b)

False

24.

Encrypted text

a)

Ciphertext

b)

Plaintext

c)

Algorithm

d)

Cipher

25.
Taking a secret message and reproducing the original plain text is known as?
a)
Vigenere Cipher
b)
Encryption
c)
Random Substitution cipher
d)
Decryption
26.

What is the algorithm of ceasar's cipher?

a)

Each letter is replaced with a particular symbol

b)

Each letter is replaced with a letter a certain number of steps down the alphabet

c)

Each letter is replaced with a particular number from 0 to 26, and numbers are replaced with letters.

d)

Each letter is replaced with a completely random number

27.
What type of key is not shared and computers cannot decrypt a message without it?
a)
Free key
b)
Private key
c)
Public key
d)
Personal key
28.
What type of key can be freely shared with anyone so that they can encrypt a message?
a)
Personal key
b)
Private key
c)
Free key
d)
Public key
29.

"Technique of combining words to hide information "

What is the above statement referring to?

a)

Crypto currency

b)

Psychology

c)

Cryptography

d)

Biology

30.

The method of hiding the actual meaning of plaintext is called

a)

key

b)

decryption

c)

encryption

d)

plaintext

31.

Using table above for Caesar Cipher, convert the plaintext "GORENG" to ciphertext

a)

HPSFOP

b)

HPSFAQ

c)

HPSFOH

d)

HPSFAD

32.

Using table above for Caesar Cipher, convert the plaintext "DUDUK" to ciphertext

a)

EVEVQ

b)

EVEVL

c)

EVEVP

d)

EVEVR

33.

A word has been encrypted with a Caesar cipher to CBU. The key used was 1. What was the original word?

a)

abc

b)

3

c)

Bat

d)

one

34.

Alan Turing helped decrypt codes that helped during which era?

a)

The Plague

b)

Word War 2

c)

The 1980s

d)

The Millennium

35.

TTSTWP HHOHAL EENANA WRITTY EICWT ASEEO.

Decrypt this message by using Transposition Cipher Method.

a)

The weather is so nice that we want to sleep

b)

The weather is so nice that we want to eat

c)

The weather is so nice that we want to study

d)

The weather is so nice that we want to play

36.

It is an attack in which the interceptor only reads the message.

a)

Active Attack

b)

Passive Attack

c)

Direct Attack

d)

Indirect Attack