Test

Question 1

Key people behind RSA

Answer 1

Ron Rivest, Adi Shamir, and Leonard Adleman

Question 2

RSA was publicly described the algorithm in

Answer 2

1977

Question 3

Applications and use cases of rsa

Answer 3

1. Digital Signatures
2. Digital Certificates
3. Secure Communication Protocols
4. Secure Key Exchange

Question 4

Blowfish designed by (name) in (year)

Answer 4

Bruce Schneier
1993

Question 5

Blowfish have (number) of bit

Answer 5

64-bit

Question 6

It is significantly faster than DES and provides a good encryption rate with no effective cryptanalysis technique found to date.

Answer 6

Blowfish Key Exchange

Question 7

The Blowfish encryption algorithm is suitable for use in scenarios where a fast, secure, and freely available encryption technique is needed. Some common use cases include:

Answer 7

1. Data Encryption
2. Network Security
3. Software Protection

Question 8

Blowfish PROS

Answer 8

Fast
Resilient
Open

Question 9

Blowfish CONS

Answer 9

Blocksize

Question 10

3DES SECURITY FEATURES:

Answer 10

1. Triple DES ( 3 DES) is a symmetric encryption algorithm based on the Data Encryption Standard ( DES).
2. It uses three successive DES operations ( encrypt- decrypt- encrypt) to achieve enhanced security.

Question 11

3DES KEY SECURITY ASPECTS:

Answer 11

1. Key Length: Uses three 56 - bit keys ( 168 bits total) for encryption, making brute- force attacks computationally infeasible.
2. Key Variability: Offers keying options ( e. g., all three keys are independent or two keys are the same) to adapt to different security requirements.
3. Block Size: Operates on 64 - bit blocks, which provides a larger data block size compared to DES.

Question 12

ADVANTAGE OF TRIPLE DES:

Answer 12

1. Robust Security: Provides a higher level of security compared to single DES due to the triple encryption process.
2. Backward Compatibility: Maintains compatibility with existing DES implementations and infrastructure.
3. Widely Adopted: Still widely used in legacy systems and environments where stronger encryption standards are required.

Question 13

DES stands for

Answer 13

Data Encryption Standard

Question 14

DES algorithm uses a key of

Answer 14

56-bit size

Question 15

DES is a block cipher with (number) rounds of (Name) structure

Answer 15

16
Feistel

Question 16

In 2002, it was overthrown by AES, which became the new standard following a public competition.

Answer 16

DES (Data Encryption Standard)

Question 17

The AES Encryption algorithm also
known as the

Answer 17

Rijndael algorithm

Question 18

AES is a symmetric block ciper algorithm with a block/chunk size of

Answer 18

128 bits

Question 19

features of AES

Answer 19

1. SP NETWORK
2. KEY EXPANSION
3. BYTE DATA
4. KEY LENGTH

Question 20

It works on an SP network structure rather than a Feistel cipher
structure, as seen in the case of the DES algorithm.

Answer 20

SP NETWORK (feature of AES)

Question 21

It takes a single key up during the first stage, which is later
expanded to multiple keys used in individual rounds.

Answer 21

KEY EXPANSION (feature of AES)

Question 22

The AES encryption algorithm does operations on byte data
instead of bit data. So it treats the 128-bit block size as 16 bytes
during the encryption procedure.

Answer 22

BYTE DATA (feature of AES)

Question 23

The number of rounds to be carried out depends on the length of the key being used to encrypt data. The 128-bit key size has ten rounds, the 192-bit 04 key size has 12 rounds, and the 256-bit key size has 14 rounds.

Answer 23

KEY LENGTH (feature of AES)

Question 24

4 STEPS OF AES ENCRYPTION
ALGORITHM

Answer 24

1. Sub Bytes
2. Shift Rows
3. Mix Columns
4. Add Round Key

Question 25

Operates on the state array by first converting each byte into its hexadecimal representation.

Answer 25

SubByte (steps of aes algorithm)

Question 26

Performs a cyclic shift on the last three rows of a state matrix.

Answer 26

ShiftRows (steps in aes algorithm)

Question 27

Operates by multiplying a constant matrix with each column in the current state array.

Answer 27

Mix Columns (steps in aes algorithm)

Question 28

The algorithm performs a bitwise XOR operation between the current state array, obtained from the prior step, and a key specific to the current round.

Answer 28

Add Round Key (steps in aes algorithm)

Question 29

A cryptographic protocol that allows two parties to establish a shared secret key over an insecure communication channel.

Answer 29

Diffie-Hellman key exchange

Question 30

Why cryptography protocols are needed for secure communication?

Answer 30

1. Confidentiality 2. Integrity 3. Authentication 4. Non-repudiation 5. Key exchange

Question 31

Diffie Hellman Key Exchange was invented by (name) and (name) in (year)

Answer 31

Whitfield Diffie and Martin Hellman in 1976

Question 32

Key Exchange Process

Answer 32

1. Parameter Selection 2. Private Key Generation 3. Public Key Computation 4. Public Key Exchange 5. Shared Secret Key Computation 6. Shared Secret Key

Question 33

Security Features of Diffie Hellman Key exchange

Answer 33

1. Perfect Forward Secrecy 2. Protection Against Eavesdropping 3. Key Exchanged without Pre-shared keys 4. Resistance to Man-in-the-Middle Attacks 5. Computational Complexity 6. Flexibility

Question 34

Applications of Diffie - Hellman

Answer 34

* Secure Communication * Key Establishment for Symmetric Encryption * VPN (Virtual Private Network) Protocols * SSH (Secure Shell) Protocol * Wireless Communication Security * Digital Signatures and Key Agreement * Secure Messaging Protocols

Question 35

Diffie Hellman Key Exchange Limitations

Answer 35

* Man-in-the-middle attacks * Vulnerabilities in specific implementations * Forward Secrecy

Question 36

Who invented Hill Cipher and in what year

Answer 36

Lester S. Hill 1929

Question 37

First polygraphic cipher

Answer 37

Hill Cipher

Question 38

Polygraphic substitution cipher based on linear algebra

Answer 38

Hill Cipher

Question 39

Each letter is represented by modulo 26

Answer 39

Hill Cipher

Question 40

Advantage of Hill Cipher

Answer 40

* Perfectly conceals single-letter frequencies * Easily solvable when dealing with 2x2 matrices * Useful when hiding a single-letter or two-letter frequency information * High diffusion and strong tamper resistance without detection * It can withstand any attack, except if the attack is through a known plaintext

Question 41

Disadvantages of Hill Cipher

Answer 41

* Vulnerable to know-plaintext attacks * A simple 2x2 matrix is quite simple. Still, when it expands, the calculations to encrypt or decrypt the data become much more complex, requiring a deep understanding of higher mathematics