NEW
Font size
WorksheetsCryptography Basics (Assignment 1)
Total questions: 58
Worksheet time: 46mins
To encrypt a message you need 2 main parts, a _________ & a key
cipher
code
algorithm
crypt
In Cryptography, original message, before being transformed, is called
Simple Text
Plain Text
Cipher Text
Filled Text
_______ is the science and art of transforming messages to make them secure and immune to attacks.
Cryptography
Cryptoanalysis
neither Cryptography nor Cryptoanalysis
either Cryptography or Cryptoanalysis
An encryption algorithm transforms plain text into:
Cipher text
Simple Text
Empty Text
Plain Text
A(n) ______ algorithm transforms cipher text to plain text.
Encryption
Decryption
A cipher is _________________________.
a person who makes up secret codes
an algorithm that is used to scramble text so that it can be passed in secret
a lock that can be used to lock a message in a lock box
any puzzle, such as a crossword or Sudoku puzzle
Plaintext
original message
coded message
algorithm for transforming plaintext to ciphertext
info used in cipher known only to sender/receiver
ciphertext
•field of both cryptography and cryptanalysis
•study of encryption principles/methods
•converting plaintext to ciphertext
•coded message
key
algorithm for transforming plaintext to ciphertext
info used in cipher known only to sender/receiver
•recovering ciphertext from plaintext
•converting plaintext to ciphertext
encipher
converting plaintext to ciphertext
coded message
•study of principles/methods of deciphering ciphertext without knowing key
study of encryption principles/methods
Confidentiality
Ensure message remains secret during transmission between parties
Ensure message is not altered while in transit between communicating partners
Verifies sender is who she says she is
Proves that nobody but on sender could have sent a particular message
Integrity
Ensure message remains secret during transmission between parties
Ensure message is not altered while in transit between communicating partners
Verifies sender is who she says she is
Proves that nobody but on sender could have sent a particular message
Authentication
Ensure message remains secret during transmission between parties
Ensure message is not altered while in transit between communicating partners
Verifies sender is who she says she is
Proves that nobody but on sender could have sent a particular message
Non-repudiation
Ensure message remains secret during transmission between parties
Ensure message is not altered while in transit between communicating partners
Verifies sender is who she says she is
Proves that nobody but on sender could have sent a particular message
It is also called as private key cryptography.
Symmetric Cryptography
Asymmetric Cryptography
Decryption Key
Hashing
One key is used for data encryption and another for data decryption.
Symmetric Cryptography
Asymmetric Cryptography
Asymmetric Key
Hashing
It is used to determine whether a message actually came from the sender that is expected and whether the message hasn't tampered with.
Hash
Key
Tag
Plaint Text
What is the meaning of cipher in cryptography?
an algorithm that performs encryption
an algorithm that generates a secret code
an algorithm that performs encryption or decryption
a secret code
Which of the following is a type of traditional cipher?
transportation cipher
transposition cipher
transforming cipher
vigenere cipher
Which of the following ciphers are created by shuffling the letters of a word?
substitution cipher
transposition cipher
vigenere cipher
Hill Cipher
What will be the ciphered text for the input string “sanfoundry” with key string as “code” to the program of keyword cipher?
SCMBNUMERY
SSCMBNUMERY
NIFO
NILO
A substitution cipher substitute one symbol with
alphabets
keys
letters
all of the above
The cryptography algorithms are divided in to ........ groups
1
2
3
4
An asymmetric key cipher uses ... keys
1
2
3
4
.................. is the original message before transmission
Plain Text
Cipher Text
encrypted text
None
Which of the following cannot be chosen as a key in the Caesar cipher?
integer
alphabet
string
none
Which of the following ciphers is a block cipher?
ceaser cipher
vignere cipher
playfair cipher
none
Hackers refers to
data alteration without permission
data update without permission
data removed without permission
all of the above
In substitution techniques the plain text letters are substituted with ----------
Another letter
Binary number
Reverse of the plain text
None of these
In transposition the plain text letters are --------------
replaced with binary numbers
reversed every time
Rearranged.
none of these
if the sender and receiver uses same key to encrypt and decrypt, then it is called as-----
Asymmetric crypto system
Symmetric Crypto System
Both
None
If the sender uses one key for encryption and receiver uses another key for decryption, then it is known as -----
Asymmetric Crypto System
Symmetric Crypto System
Both
None
The ------------ converts one block of plain text into one block of cipher text at a time.
Caesar cipher
Stream cipher
Block cipher
Play fair cipher
What is cipher text when k=4 according to Captain Midnight Code for the plain text "AFTER"
ejxiy
ejxiw
ejxjv
ejxiv
Data Encryption Standard (DES) is a __________.
Stream Cipher
Bit Cipher
Block Cipher
Substitution Cipher
How many rounds does the AES-256 perform?
10
12
14
16
__________ involves the passive capture of a data unit and its subsequent retransmission to produce an unauthorized effect.
Disruption
Replay
Service denial
Masquerade
A common technique for masking contents of messages or other information traffic so that opponents can not extract the information from the message is____________
integrity
encryption
analysis
masquerade
A __________ takes place when one entity pretends to be a different entity
replay
masquerade
passive attack
service denial
__________ is the protection of transmitted data from passive attacks
Access control
Data control
Nonrepudiation
Confidentiality
The protection of the information that might be derived from observation of traffic flows is _________
connectionless confidentiality
connection confidentiality
traffic- flow confidentiality
selective- field confidentiality
A _________ level breach of security could cause a significant degradation in mission capability to an extent and duration that the organization is able to perform its primary functions, but the effectiveness of the functions is significantly reduced.
catastrophic
moderate
low
high
The methods of __________ conceal the existence of the message in a graphic
image.
steganography
decryptology
cryptology
cryptography
A way to improve on the simple monoalphabetic technique is to use different monoalphabetic substitutions as one proceeds through the plaintext message. The general name for this approach is ___________ .
rail fence cipher
cryptanalysis
polyanalysis cipher
polyalphabetic substitution cipher
If both sender and receiver use the same key, the system is referred to as ___________
public-key encryption
asymmetric
two-key
conventional encryption
A technique referred to as a __________ is a mapping achieved by performing some sort of permutation on the plaintext letters
transposition cipher
Caesar cipher
polyalphabetic cipher
monoalphabetic cipher
