Question 1

Encryption is the practice of transforming information so that it is secure and cannot be accessed by unauthorized parties.

Accepted Answer

False

Question 2

What is a block cipher algorithm that operates on 64-bit blocks and can have a key length from 32 to 448 bits?
A)Twofish
B)Blowfish
C)Whirlpool
D)Rijndal

Accepted Answer

Blowfish is a symmetric block cipher that can encrypt data in 64-bit blocks and supports variable-length keys from 32 bits up to 448 bits, making it flexible for both domestic and exportable use.

Question 3

A collision attack is an attempt to find two input strings of a hash function that produce the same hash result.

Accepted Answer

This is correct, a collision attack involves finding two input strings that produce the same hash result. This can be a security vulnerability in hash functions, as it allows an attacker to generate inputs that would be falsely identified as legitimate.

Question 4

Wireless data networks are particularly susceptible to known ciphertext attacks.

Accepted Answer

Wireless data networks are more vulnerable to known ciphertext attacks as the encrypted messages and keys are transmitted over the air and can be intercepted by an attacker. This allows the attacker to obtain the ciphertext and the corresponding plaintext, allowing them to analyze the encryption algorithm and potentially break the security of the network.

Question 5

GNU Privacy Guard a proprietary software that runs on different operating systems.

Accepted Answer

GNU Privacy Guard (GnuPG) is not a proprietary software, it is a free and open-source software that runs on various operating systems.

Question 6

The XOR cipher is based on the binary operation eXclusive OR that compares two bits.

Accepted Answer

The XOR cipher (also known as the Vernam cipher) is indeed based on the binary operation eXclusive OR (XOR) that compares two bits.

Question 7

One of the first popular symmetric cryptography algorithms was RSA.

Accepted Answer

RSA is actually an asymmetric cryptography algorithm, not symmetric.

Question 8

The simplest type of stream cipher,one in which one letter or character is exchanged for another,is known as what?
A)shift
B)substitution
C)lock
D)loop

Accepted Answer

The definition provided clearly indicates the type of cipher as a substitution cipher. A shift cipher only shifts letters by a fixed amount, whereas a substitution cipher replaces each character with another, which is the case here. Choice A, C, and D describe things that have no relevance to the question.

Question 9

In which type of encryption is the same key used to encrypt and decrypt data?
A)private
B)public
C)symmetric
D)asymmetric

Accepted Answer

Symmetric encryption uses the same key to both encrypt and decrypt data. Examples of symmetric encryption include AES, DES, and Blowfish. Private and asymmetric encryption involve the use of different keys for encryption and decryption, and public encryption involves the use of a key for encryption that can be distributed publicly, but a separate private key for decryption.

Question 10

Asymmetric cryptographic algorithms are also known as private key cryptography.

Accepted Answer

Asymmetric cryptographic algorithms are also known as public key cryptography, not private key cryptography. Private key cryptography refers to symmetric key algorithms where the same key is used for both encryption and decryption.

Question 11

If using the MD5 hashing algorithm,what is the length to which each message is padded?
A)32 bits
B)64 bits
C)128 bits
D)512 bits

Accepted Answer

MD5 algorithm pads the message to ensure its length in bits is congruent to 448, modulo 512. This padding brings the total length to a multiple of 512 bits, but the specific padding length can vary depending on the original message length. The choice refers to the block size to which the message is extended, not the length of the padding itself.

Question 12

Obfuscation is making something well known or clear.

Accepted Answer

Obfuscation is the deliberate obscuring or confusion of information to make it more difficult to understand. It is the opposite of making something clear or well known.

Question 13

Which type of cryptographic algorithm takes an input string of any length,and returns a string of any requested variable length?
A)substitution
B)block
C)loop
D)sponge

Accepted Answer

The cryptographic algorithm that takes an input string of any length and returns a string of any requested variable length is a sponge function. The sponge function is a subclass of SHA-3 (Secure Hash Algorithm 3) that is suitable for a wide range of applications including message authentication, digital signatures, and pseudo-random number generation. The sponge function has been designed to be extremely resistant to cryptanalysis and so is considered to be one of the most secure cryptographic algorithms currently available.

Question 14

Which of the following is not one of the functions of a digital signature?
A)verification of the sender
B)prevention of the sender from disowning the message
C)prove the integrity of the message
D)protect the public key

Accepted Answer

Digital signatures do not protect the public key. Their main functions are to verify the sender, ensure the integrity of the message, and prevent the sender from disowning the message.

Question 15

Ciphertext is the scrambled and unreadable output of encryption.

Accepted Answer

Ciphertext is the encrypted message that is unreadable without the decryption key.

Question 16

What type of cryptography uses two keys instead of just one,generating both a private and a public key?
A)symmetric
B)asymmetric
C)shared
D)open

Accepted Answer

Asymmetric cryptography uses two keys - a private key and a public key. The private key is kept secret by the owner and is used for decryption, while the public key is freely available and is used for encryption. This makes it more secure than symmetric cryptography as only the owner of the private key can decrypt the data, even if someone intercepts the public key.

Question 17

Which of the following asymmetric cryptography algorithms is most commonly used?
A)AES
B)RSA
C)Twofish
D)Blowfish

Accepted Answer

RSA is the most commonly used asymmetric cryptography algorithm for tasks such as secure data transmission and digital signatures. AES, Twofish, and Blowfish are all symmetric cryptography algorithms.

Question 18

Which standard was approved by NIST in late 2000 as a replacement for DES?
A)AES
B)3DES
C)RSA
D)Twofish

Accepted Answer

AES (Advanced Encryption Standard) was approved by NIST in late 2000 as a replacement for DES. It is now widely used as the preferred symmetric encryption standard for government and commercial use.

Question 19

In information technology,non-repudiation is the process of proving that a user performed an action.

Accepted Answer

Non-repudiation is indeed the process of proving that a user performed an action in information technology. It is often used in digital transactions to prevent one party from denying that they carried out a particular action or transaction.

Question 20

After the DES cipher was broken and no longer considered secure,what encryption algorithm was made as its successor?
A)AES
B)Twofish
C)3DES
D)RSA

Accepted Answer

3DES (Triple DES) was developed as a more secure version of DES by applying the DES algorithm three times to each data block.

Quiz 3: Basic Cryptography

Encryption is the practice of transforming information so that it is secure and cannot be accessed by unauthorized parties.

What is a block cipher algorithm that operates on 64-bit blocks and can have a key length from 32 to 448 bits?

A collision attack is an attempt to find two input strings of a hash function that produce the same hash result.

Wireless data networks are particularly susceptible to known ciphertext attacks.

GNU Privacy Guard a proprietary software that runs on different operating systems.

The XOR cipher is based on the binary operation eXclusive OR that compares two bits.

One of the first popular symmetric cryptography algorithms was RSA.

The simplest type of stream cipher,one in which one letter or character is exchanged for another,is known as what?

In which type of encryption is the same key used to encrypt and decrypt data?

Asymmetric cryptographic algorithms are also known as private key cryptography.

If using the MD5 hashing algorithm,what is the length to which each message is padded?

Obfuscation is making something well known or clear.

Which type of cryptographic algorithm takes an input string of any length,and returns a string of any requested variable length?

Which of the following is not one of the functions of a digital signature?

Ciphertext is the scrambled and unreadable output of encryption.

What type of cryptography uses two keys instead of just one,generating both a private and a public key?

Which of the following asymmetric cryptography algorithms is most commonly used?

Which standard was approved by NIST in late 2000 as a replacement for DES?

In information technology,non-repudiation is the process of proving that a user performed an action.

After the DES cipher was broken and no longer considered secure,what encryption algorithm was made as its successor?