WorksheetsCryptographic Algorithms(Assignment 3)
Total questions: 100
Worksheet time: 2hrs 40mins
A(n) _____________ is a keyless substitution cipher with N inputs and M outputs that uses a formula to define the relationship between the input stream and the output stream
S-box
P-box
T-box
none of the mentioned
A(n) _____________ is a keyless substitution cipher with N inputs and M outputs that uses a table to define the relationship between the input
S-box
P-box
T-box
None of the ementioned
A modern cipher is usually a complex _____ cipher made of a combination of different simple ciphers.
round
circle
square
None of the mentioned
DES is a(n) _______ method adopted by the US government.
symmetric-key
asymmetric-key
Nither symmetric-key nor asymmetric-key
Both symmetric-key and asymmetric-key
DES has an initial and final permutation block and _____ rounds.
14
15
16
None of the mentioned
The DES function has _____ components
2
3
4
5
DES uses a key generator to generate sixteen _____ round keys.
32-bit
48-bit
54-bit
42-bit
___________ DES was designed to increase the size of DES Key
Double
Triple
Quadruple
None of the mentioned
One commonly used public-key cryptography method is the ___ algorithm
RSS
RAS
RSA
RAA
The _____ method provides a one-time session key for two parties
Diffie-Hellman
RSA
DES
AES
Which one of the following algorithm is not used in asymmetric-key cryptography?
RSA algorithm
Diffie-hellman algorithm
Electronic code book algorithm
DSA algorithm
An asymmetric-key cipher uses
1 Key
2 Keys
3 Keys
4 Keys
Find x for the CRT when x= 2 mod 3; x= 3 mod 5; x = 2 mod 7
33
22
23
31
In asymmetric key cryptography, the private key is kept by
Sender
Receiver
Sender & Receiver
All the connected devices to the network
In an asymmetric key cipher the sender uses which key?
Private
Public
Either a or b
Neither a nor b
. _______ is a round cipher uses a 128-bit block of data
AEE
AED
AER
AES
The ________ method provides a one time session key for 2 parties
Diffie-Hellman
RSA
DES
AES
AES has ......... different configurations
2
3
4
5
Public-key cryptography is also known as ?
Asymmetric cryptography
Symmetric cryptography
Both A and B
None of the above
Private key algorithm is used for _____ encryption and public key algorithm is used for _____ encryption.
Messages, session key
Session key, messages
Can be used for both
None of the above
AES uses a ____________ bit block size and a key size of __________ bits.
a) 128; 128 or 256
b) 64; 128 or 192
c) 256; 128, 192, or 256
d) 128; 128, 192, or 256
Like DES, AES also uses Feistel Structure.
a) True
b) False
How many rounds does the AES-192 perform?
a) 10
b) 12
c) 14
d) 16
How many rounds does the AES-256 perform?
a) 10
b) 12
c) 14
d) 16
What is the expanded key size of AES-192?
a) 44 words
b) 60 words
c) 52 words
d) 36 words
The 4×4 byte matrices in the AES algorithm are called
a) States
b) Words
c) Transitions
d) Permutations
In AES the 4×4 bytes matrix key is transformed into a keys of size __________
a) 32 words
b) 64 words
c) 54 words
d) 44 words
here is an addition of round key before the start of the AES round algorithms.
a) True
b) False
Which of the following is a mode of operation for the Block ciphers in cryptography?
Electronic Code Book (ECB)
Cipher Block Chaining (CBC)
Counter (CTR) mode
All of the above
Which one of the following is not a possible key length for the Advanced Encryption Standard Rijndael cipher?
A. 56 bits
B. 128 bits
C. 192 bits
D. 256 bits
Explain the working principle of symmetric encryption.
Symmetric encryption uses a different key for encryption and decryption.
Symmetric encryption does not require any key for encryption and decryption.
Symmetric encryption uses the same key for both encryption and decryption.
Symmetric encryption uses a public key for encryption and a private key for decryption.
What is symmetric encryption?
A type of encryption that can only be used for text-based data
A type of encryption where different keys are used for encryption and decryption
A type of encryption where the same key is used for both encryption and decryption
A type of encryption that doesn't require a key
What is asymmetric encryption?
A type of encryption that is extremely easy to break
A type of encryption using only one key to encrypt and decrypt data
A type of encryption that is no longer used in modern technology
A type of encryption using a pair of keys (public and private) to encrypt and decrypt data
How does asymmetric encryption differ from symmetric encryption?
Asymmetric encryption is faster than symmetric encryption.
Asymmetric encryption uses the same key for both encryption and decryption.
Asymmetric encryption uses a pair of public and private keys.
Asymmetric encryption does not require any keys.
What is the purpose of Transport Layer Security (TLS) in network security?
To make network communication less secure
To provide secure communication over a computer network.
To provide faster internet speed
to enable VPN to work
What is a digital certificate and how is it used in the context of security?
It is a form of encryption used to hide sensitive information
It is a type of physical key used to unlock digital files
It is a secure software program that protects against computer hacking
It is a digital document that verifies the identity of a website or individual and is used to establish secure connections and authenticate identities.
How does PKI ensure secure communication?
By using digital certificates to authenticate and encrypt data
By using plain text to transmit data
By sharing private keys openly
By using weak encryption algorithms
What is quantum cryptography?
A type of ancient encryption using hieroglyphics
A method of communication using Morse code
A form of cryptography based on astrology
A method of secure communication using quantum mechanics
Discuss the potential impact of quantum cryptography on traditional encryption methods.
Quantum cryptography can render traditional encryption methods obsolete.
Quantum cryptography has no impact on traditional encryption methods
Quantum cryptography is not a viable alternative to traditional encryption methods
Traditional encryption methods are more secure than quantum cryptography
Describe the process of obtaining a digital certificate and its role in ensuring secure communication.
The process involves generating a public and private key pair, submitting a CSR to a certificate authority, and receiving the digital certificate after verification. Its role is to provide authentication, encryption, and data integrity for secure communication.
The process involves creating a public and private key pair, and its role is to block unauthorized access to the network.
The process involves creating a public key, submiting a CSR, and its role is to block unauthorized access to the network.
The process requires obtaining a certificate from the an authority, and its role is to provide proof of identity for online transactions.
What are the common protocols used for secure communication over the internet?
FTP, POP3, and Telnet
HTTPs, FTPs, and SMTP
TCPs, IP, and UDPs
HTTPS, SSL/TLS, and SSH
Which of the following is not part of security?
non-repudiation
user authentication
data integrity
data privacy
user identity
Explain the concept of public key infrastructure (PKI) and its role in ensuring secure communication.
PKI is a type of encryption used to hide sensitive information
PKI is a system for managing digital certificates and public-private key pairs
PKI is a method of secure communication using Morse code
PKI is a form of cryptography based on astrology
What is the significance of digital signatures in ensuring data integrity and authenticity?
Digital signatures are used to encrypt data for secure transmission
Digital signatures are used to verify the identity of a website or individual
Digital signatures are used to ensure the integrity and authenticity of a message or document
Digital signatures are used to provide faster internet speed
1) avoids the need to utilise computer time during each TLS connection
2) TLS can establish either a new session or attempt to resume an existing session …
3) … the latter can save considerable computer time.
These are descriptions for......
handshake protocol
session caching
PKI
record protocol
Discuss the role of SSL/TLS protocols in securing online transactions and communication.
SSL/TLS protocols are used to make network communication less secure
SSL/TLS protocols are used to provide secure communication over a computer network
SSL/TLS protocols are used to enable VPN to work
SSL/TLS protocols are used to provide proof of identity for online transactions
What is a digital signature and how does it provide authentication and integrity in digital communication?
A digital signature is a type of protection for sensitive information
A digital signature is a document used to put signature on a digital document.
A digital signature is a cryptographic technique used to verify the authenticity and integrity of a message or document.
A digital signature is a type of encryption used to hide the content of a message.
SSL provides which of the following?
confidentiality
compression, message integrity and confidentiality
Authentication, encription, and digital signatures
Message integrity
1) permits website and client to authenticate each other and to make use of encryption
algorithms
2) secure session between client and website is established.
This describes....
Record Protocol
Handshake protocol
session caching
QKD
Which of these are not contained in Digital Certificate?
name of company/organisation
company address
signature algorithm used.
company details/identifier
serial number.
CA that issued the certificate
CA digital signature
period during which certificate is valid
Question 1: What is the smallest prime number?
5
1
2
3
Question 2: How many prime numbers are there between 1 and 10?
8
4
6
2
Question 5: What is 7 mod 3?
2
4
6
1
Question 6: What is 12 mod 5?
2
10
7
3
Question 7: What is the process of encrypting a message using a public key?
Using the sender's private key to encode the message
Using the recipient's public key to encode the message
Using a random key to encode the message
Using the recipient's private key to encode the message
Question 8: What is the process of decrypting a message using a private key?
Symmetric decryption
Public key encryption
Asymmetric decryption
Hashing
Question 9: How are public and private keys generated in asymmetric key cryptography?
By guessing and checking different combinations
By using a random number generator
By using a simple substitution cipher
Using mathematical algorithms such as RSA or ECC
Question 10: What is the key length typically used in asymmetric key cryptography?
512 bits
256 bits
1024 bits
2048 bits
The DES Algorithm Cipher System consists of ____________rounds (iterations) each with a round key
12
18
9
16
The DES algorithm has a key length of ______ bits
128
56
192
256
What is the size of the key in the SDES algorithm?
10 bits
20 bits
56 bits
64 bits
AES uses a ____________ bit block size and a key size of __________ bits.
128; 128 or 256
64; 128 or 192
256; 128, 192, or 256
128; 128, 192, or 256
Like DES, AES also uses Feistel Structure
True
False
The 4×4 byte matrices in the AES algorithm are called
States
Words
Transposition
Permutation
The acronym AES stands for?
American Encryption Standard
Advanced Encryption System
Advanced Encryption Standard
Advanced Encryption Standard
Which of the following is a mode of operation for the Block ciphers in cryptography?
Electronic Code Book (ECB)
Cipher Block Chaining (CBC)
Counter (CTR) mode
All of the above
Which of the following modes of operations can be followed for both stream ciphers as well as block ciphers?
CBC (Cipher Block Chaining)
ECB (Electronic Code Book)
CFB (Cipher text Feed Back)
All of the above
DES follows
Feistel Cipher Structure
SP Networks
Hash Algorithm
Caesars Cipher
In RSA, Ф(n) = _______ in terms of p and q.
(p)/(q)
(p)(q)
(p-1)(q-1)
(p+1)(q+1)
RSA is named after the researchers (_____ ) who proposed it
River, Shamir, Adleman
Rivest, Shamus, Adleman
Rivest, Shamir, Adleman
Rivest, Shamir, Adlemar
Richard received an encrypted message sent to him from Sue. Which key should he use to decrypt the message?
Richard's public key
Richard's private key
Sue's public key
A. Sue's private key
In the RSA public key cryptosystem, which one of the following numbers will always be largest?
e
n
p
q
In the RSA algorithm, we select 2 random large values ‘p’ and ‘q’. Which of the following is the property of ‘p’ and ‘q’?
p and q should be divisible by Ф(n)
p and q should be co-prime
p and q should be prime
p/q should give no remainder
Asymmetric key cipher uses_____ key
one
two
three
four
For RSA to work,the value of M must be less than
p
q
n
r
ᶲ(19)=
14
13
18
17
gcd( 18,300) =
4
2
8
6
73 mod 19 =
18
1
14
12
Encryption: What is the process of converting plaintext into ciphertext using a secret key?
Randomization
Translation
Decryption
Encryption
Encryption: Which type of cipher uses the same key for both encryption and decryption?
Asymmetric key cipher
Symmetric key cipher
Hash function
Public key cipher
Encryption: What is the name of the algorithm used for encrypting data in symmetric key ciphers?
AES
RSA
MD5
SHA-256
Decryption: What is the process of converting ciphertext back into plaintext using the secret key?
Obfuscation
Decryption
Encoding
Encryption
Decryption: In symmetric key ciphers, is the decryption process the reverse of the encryption process?
Only on weekends
Sometimes
No
Yes
Decryption: What is the name of the algorithm used for decrypting data in symmetric key ciphers?
Same algorithm
Different algorithm
No algorithm
Asymmetric algorithm
Key generation: How are the secret keys generated in symmetric key ciphers?
Using a random number generator or a pseudorandom number generator
Using a prime number generator
Using a sequential number generator
Using a fixed number generator
Key generation: What is the importance of key generation in symmetric key ciphers?
Key generation is not important in symmetric key ciphers
Key generation ensures the strength and security of the encryption
Key generation only adds complexity without improving security
The strength of encryption is not affected by key generation
Key generation: What is the term used for the process of creating a key schedule in symmetric key ciphers?
Key Expansion
Key Shrinkage
Key Compression
Key Contraction
Block ciphers: What is the size of the block in block ciphers?
The size of the block in block ciphers is typically 64 or 128 bits.
The size of the block in block ciphers is typically 32 bits.
The size of the block in block ciphers is typically 256 bits.
The size of the block in block ciphers is typically 512 bits.
Block ciphers: Which type of cipher processes the input one bit at a time?
Block cipher
Transposition cipher
Substitution cipher
Stream cipher
Block ciphers: What is the name of the popular block cipher that uses a 64-bit block size?
RSA
DES
SHA-256
AES
Stream ciphers: How does a stream cipher encrypt plaintext?
By converting the plaintext into a different character set
By using a fixed key to encrypt the plaintext
By generating a stream of key-dependent pseudo-random bits and combining them with the plaintext using a bitwise XOR operation.
By rearranging the plaintext characters in a random order
Stream ciphers: Which type of cipher encrypts one bit of plaintext at a time?
Block cipher
Stream cipher
MD5 hash function
RSA encryption
Stream ciphers: What is the name of the stream cipher that is widely used in network security protocols?
AES
DES
RC4
Blowfish
Explain the concept of modular arithmetic and its applications in real life.
Modular arithmetic is a system of arithmetic for fractions, where numbers are rounded up to the nearest whole number.
Modular arithmetic is a system of arithmetic for decimals, where numbers are rounded to the nearest tenth.
Modular arithmetic is a system of arithmetic for integers, where numbers wrap around after reaching a certain value. It has applications in cryptography, computer science, and music theory.
Modular arithmetic is a system of arithmetic for negative numbers, where numbers are multiplied by -1.
In Extended Euclidean Algorithm do the repetition until get the remainder is
1
2
0
any number
In Euclidean Algorithm do the repetition until get the remainder is
1
2
0
any number
The art and science of breaking the cipher text is known as
Cryptanalysis
Cryptography
Staganography
Watermarking
_______ 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
15 ≡ -3 (mod 9)
True
False
Can not say
None of these
