funsec4e_CH07_TB

Alice would like to send a message to Bob using a digital signature. What cryptographic key does Alice use to create the digital signature?

Alice's private key

Bob received a message from Alice that contains a digital signature. What cryptographic key does Bob use to verify the digital signature?

Alice's public key

Which cryptographic attack is relevant in only asymmetric key systems and hash functions?

Chosen ciphertext

Alice and Bob would like to communicate with each other using a session key, but they do not already have a shared secret key. Which algorithm can they use to exchange a secret key?

Diffie-Hellman

What is not a symmetric encryption algorithm?

Diffie-Hellman

Security objectives add value to relationships between businesses or between businesses and their customers. Which objective binds a message or data to a specific entity?

Digital signature

Which of the following is not an objective of cryptanalysis, the process of breaking codes?

Encrypt the plaintext of a target message

A digitized signature is a combination of a strong hash of a message and a secret key.

False

A private key cipher is also called an asymmetric key cipher.

False

A product cipher is an encryption algorithm that has no corresponding decryption algorithm.

False

In a known-plaintext attack (KPA), the cryptanalyst has access only to a segment of encrypted data and has no choice as to what that data might be.

False

The U.S. government currently has no standard for creating cryptographic keys for classified applications.

False

The term certificate authority (CA) refers to a trusted repository of all public keys.

False

True or False? A block cipher encrypts one byte (or bit) at a time, whereas a stream cipher encrypts an entire block of data at a time.

False

You must always use the same algorithm to encrypt information and decrypt the same information.

False

A salt value is a set of random characters you can combine with an input key to create an encryption key.

True

An algorithm is a repeatable process that produces the same result when it receives the same input.

True

Digital signatures require asymmetric key cryptography.

True

Elliptic curve cryptography (ECC) relies on algebraic structures of elliptic curves over finite fields.

True

In cryptography, a keyspace is the number of possible keys to a cipher.

True

Revocation is a security measure that stops authorization for access to data.

True

Symmetric key ciphers require that both parties first exchange keys to be able to securely communicate.

True

Transport Layer Security (TLS) is an example of a transport encryption protocol.

True

Which information security objective verifies the action to create an object or verifies an object's existence by an entity other than the creator?

Witnessing

Bob is sending a message to Alice. He wants to ensure that nobody tampers with the message while it is in transit. What goal of cryptography is Bob attempting to achieve?

Integrity

Juan is a wireless security professional. He is selecting a standard for wireless encryption protocols for access points and devices for his agency. For the highest security, which protocol should Juan choose?

Wi-Fi Protected Access version 3 (WPA3)

Bob is sending a message to Alice. He wants to ensure that nobody can read the content of the message while it is in transit. What goal of cryptography is Bob attempting to achieve?

Confidentiality

Some ciphers, regardless of type, rely on the difficulty of solving certain mathematical problems, which is the basis for asymmetric key cryptography. Which of the following is a branch of mathematics that involves multiplicative inverses that these ciphers use?

Field theory

What is the only unbreakable cipher when it is used properly?

Vernam

Maria receives a ciphertext message from her colleague Wen. What type of function does Maria need to use to read the plaintext message?

Decryption

When Alice receives a message from Bob, she wants to be able to demonstrate to Miriam that the message actually came from Bob. What goal of cryptography is Alice attempting to achieve?

Nonrepudiation

Which approach to cryptography uses highly parallel algorithms that could solve problems in a fraction of the time needed by conventional computers?

Quantum cryptography

Which type of cipher works by rearranging the characters in a message?

Transposition

A keyword mixed alphabet cipher uses a cipher alphabet that consists of a keyword, minus duplicates, followed by the remaining letters of the alphabet.

True

Alice would like to send a message to Bob securely and wishes to use asymmetric encryption to encrypt the contents of the message. What key does she use to encrypt this message?

Bob's public key

Which of the following is not true of hash functions?

The hashes produced by a specific hash function may vary in size.

You can break a cipher by analyzing the ciphertext to find the plaintext or key or by analyzing the ciphertext and its associated plaintext to find the key.

True

Whereas a cipher performs a particular task, a key gives the specific directions for how to do it.

True

With asymmetric key ciphers, it is computationally infeasible to derive the second algorithm from the first algorithm.

True

Which set of characteristics describes the Caesar cipher accurately?

Symmetric, stream, substitution