38 Questions
What operation is used to combine the plaintext with the key stream in RC4 encryption?
Bit-wise exclusive OR
What is used to generate the key stream in RC4 encryption?
Pseudo-random generating technique
Which organization banned the usage of RC4 in TLS protocols in 2015?
Internet Engineering Task Force (IETF)
What additional investigation is required before implementing new systems using RC4?
Security analysis
What is RC4A+ in relation to the basic RC4 algorithm?
A more complex version with a longer key schedule
What type of attack can be carried out if RC4 encryption is not used with a robust MAC?
Bit-flipping attack
How is authentication handled in RC4 stream ciphers?
Authentication is not possible using RC4 stream ciphers.
According to the text, what size range can the variable-length key have when initializing RC4?
Between 1 and 256 bytes
What is a key characteristic of symmetric key algorithms?
The sender and receiver must share the same secret key
Why are symmetric key algorithms considered faster and more efficient?
They require less computation compared to asymmetric key algorithms
In symmetric key algorithms, what happens if the sender and receiver do not share the secret key?
The message cannot be decrypted
What distinguishes symmetric key algorithms from asymmetric key algorithms in terms of security?
They are considered less secure
Which aspect of symmetric key algorithms makes them suitable for internet communication?
Fast encryption and decryption capabilities
What is one of the weaknesses found in DES in the last few years?
Vulnerability to weak keys
What property of DES is responsible for a small change in plaintext causing a significant change in ciphertext?
Avalanche effect
What is the significant difference between DES and IDEA regarding key length?
DES uses 56-bit keys, while IDEA uses 128-bit keys
In IDEA, what is the purpose of the XOR operations in each round?
To introduce non-linearity
What happens during the output transformation step in IDEA after all rounds?
Four sub-blocks are formed
What factor determines the cryptographic strength of a symmetric key algorithm related to the size of the key used?
Key size
Which type of symmetric key algorithm is known for its efficiency and ease of implementation due to being based on a structure called a Feistel network?
Feistel ciphers
What characteristic distinguishes stream ciphers from block ciphers in terms of their encryption process?
Faster and more efficient operation
Which factor contributes to the cryptographic strength of a symmetric key algorithm by increasing the number of times encryption and decryption processes are repeated?
Number of rounds
What is a major drawback associated with symmetric key algorithms as compared to asymmetric key algorithms?
Need for sharing secret keys
What is a characteristic of a block cipher?
Ensures the same plaintext block encrypts to different ciphertext with the same key.
In Cipher Block Chaining (CBC) mode, what does the encryption scheme involve?
XORing the plaintext with the prior ciphertext block prior to encryption.
What is a distinguishing feature of Output Feedback (OFB) mode in block ciphers?
Employs an internal feedback structure independent of plaintext.
What is a key characteristic of DES (Data Encryption Standard)?
Uses 8 bits of the key for check bits.
What does the DES function apply to produce a 32-bit output?
Expansion Permutation Box
What is the size of the key used in IDEA encryption?
128 bits
How many rounds are there in the IDEA encryption process?
8 rounds
In IDEA encryption, what happens in the final step before producing the output?
Four sub-keys (K49 to K52) are used in an output transformation
What is the significance of circular left shifts in generating sub-keys for different rounds in IDEA encryption?
They help in mixing and shuffling the key bits effectively
Which operation is NOT utilized in the rounds of IDEA encryption?
Bitwise OR operation
What type of operation is used to combine the plaintext with the key stream in RC4 encryption?
Bitwise XOR
Which organization recommended limiting the use of RC4 encryption due to threat vulnerabilities?
Microsoft
What is a notable drawback identified in using RC4 stream ciphers?
Inability to operate with small data streams
What is the purpose of the Key-Scheduling Algorithm (KSA) in RC4 encryption?
Generate the permutation of 256 available bytes
What is the most significant advantage of using RC4 stream ciphers?
Simplicity in construction and ease of use
Test your knowledge on symmetric key algorithms, a type of cryptographic technique that uses a shared secret key for encryption and decryption. Learn about the efficiency of symmetric key algorithms compared to asymmetric key algorithms, and the importance of sharing a secret key between the sender and receiver.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
