Question 1

A public-key encryption scheme has __________ ingredients.

Accepted Answer

The answer of A public-key encryption scheme has __________ ingredients.
...

Question 2

Asymmetric encryption transforms plaintext into __________ using one of two keys and an encryption algorithm.

Accepted Answer

The answer of Asymmetric encryption transforms plaintext into __________ using...

Question 3

The scrambled message produced as output is the __________ .It depends on the plaintext and the key.

Accepted Answer

The answer of The scrambled message produced as output is...

Question 4

"The sender 'signs' a message with its private key.Signing is achieved by a cryptographic algorithm applied to the message or to a small block of data that is a function of the message," is a description of a ___________ .

Accepted Answer

The answer of "The sender 'signs' a message with its...

Question 5

The readable message or data that is fed into the algorithm as input is the ____________ .

Accepted Answer

The readable message or data that is fed into the algorithm as input is known as plaintext. Ciphertext is the result of the encryption process, exchange refers to the transmission of the message, and encryption is the process of converting plaintext into ciphertext.

Question 6

The key used in symmetric encryption is referred to as a __________ key.

Accepted Answer

Symmetric encryption uses a single secret key for both encryption and decryption. This key is kept secret and must be known by both the sender and the recipient to communicate securely. Therefore, the key used in symmetric encryption is referred to as a secret key.

Question 7

Public-key algorithms are based on __________ .

Accepted Answer

Public-key algorithms are based on mathematical functions, specifically number theory. They use large prime numbers and other mathematical concepts to create keys that are used for encryption and decryption. Permutation and substitution are techniques used in symmetric-key algorithms. Symmetry is a property of objects having the same features or form on opposite sides of a dividing line or plane.

Question 8

We define the ___________ of an algorithm to be fn)if,for all n and all inputs of length n the execution of the algorithm takes at most fn)steps.This is a common measure of the efficiency of an algorithm.

Accepted Answer

Time complexity is the measure of the efficiency of an algorithm based on the maximum number of steps it takes to execute for any input of length n. The notation often used for time complexity is O(f(n)), where f(n) represents the upper bound of the number of steps taken by the algorithm for an input of size n. Thus, the correct answer is A - time complexity. One-way function, timing attack, and OAEP are not related to the efficiency of algorithms in terms of their time complexity.

Question 9

__________ are two related keys,a public key and a private key that are used to perform complementary operations,such as encryption and decryption or signature generation and signature verification.

Accepted Answer

Asymmetric keys, also known as public-key cryptography, use two related keys – a public key and a private key – to perform complementary operations. The public key is used for encryption and signature verification, while the private key is used for decryption and signature generation. This approach allows for secure communication and authentication without requiring the exchange of a secret key beforehand, as is required with symmetric key cryptography. Key exchanges and cipher keys are not the same as asymmetric keys, and do not involve the use of a public and private key pair.

Question 10

The __________ indicates that the subscriber identified in the certificate has sole control and access to the private key.

Accepted Answer

The statement is referring to the concept of non-repudiation, which is provided by digital certificates. Specifically, the subscriber's private key is used to create digital signatures that can only be verified with the corresponding public key contained in the certificate. This indicates that the subscriber has sole control over the private key, which provides assurance that the signature was created only by the subscriber and cannot be repudiated.

Question 11

The difficulty of attacking __________ is based on the difficulty of finding the prime factors of a composite number.

Accepted Answer

The answer of The difficulty of attacking __________ is based...

Question 12

A __________ is a digital document issued and digitally signed by the private key of a Certification Authority that binds the name of a subscriber to a public key.

Accepted Answer

The answer of A __________ is a digital document issued...

Question 13

A __________ is when two sides cooperate to exchange a session key.

Accepted Answer

The answer of A __________ is when two sides cooperate...

Question 14

A __________ is a cryptographic algorithm that uses two related keys,a public key and a private key.The two keys have the property that deriving the private key from the public key is computationally infeasible.

Accepted Answer

The description matches the definition of a public key asymmetric cryptographic algorithm, which uses a pair of related keys (public and private) that cannot be easily derived from each other. RSA is an example of a public key algorithm, but it is not the only one. Option A is incorrect because it describes a symmetric algorithm, which uses the same key for encryption and decryption. Option B describes a process for securely exchanging keys between two parties, but it is not a cryptographic algorithm itself.

Question 15

Two issues to consider with the computation required to use RSA are encryption/decryption and __________ .

Accepted Answer

Key generation is a critical issue in RSA as it involves generating large prime numbers and computing the modulus, which is computationally intensive.

Question 16

__________ depend on the running time of the decryption algorithm.

Accepted Answer

Timing attacks depend on the running time of the decryption algorithm. This type of attack involves measuring the time taken to execute the decryption algorithm on various inputs and using this information to deduce the secret key.

Question 17

The __________ is a set of policies,processes,server platforms,software and workstations used for the purpose of administering certificates and public-private key pairs,including the ability to issue,maintain,and revoke public key certificates.

Accepted Answer

The answer of The __________ is a set of policies,processes,server...

Question 18

__________ encryption is a form of cryptosystem in which encryption and decryption are performed using a public key and a private key.

Accepted Answer

The answer of __________ encryption is a form of cryptosystem...

Question 19

Public-key cryptography is asymmetric,involving the use of two separate keys,in contrast to ___________ encryption,which uses only one key.

Accepted Answer

The answer of Public-key cryptography is asymmetric,involving the use of...

Question 20

A __________ is one that maps a domain into a range such that every function value has a unique inverse,with the condition that the calculation of the function is easy,whereas the calculation of the inverse is infeasible.

Accepted Answer

The answer of A __________ is one that maps a...

Quiz 9: Public-Key Cryptography and Rsa