15.0 Cryptography (Ethical Hacking)

Your company produces an encryption device that lets you enter text and receive encrypted text in response. An attacker obtains one of these devices and starts inputting random plain text to see the resulting ciphertext. Which of the following cryptographic attacks is being used? Known plain text Chosen plain text Brute force Chosen ciphertext

Chosen plain text

Which of the following encryption tools would prevent a user from reading a file that they did not create and does not require you to encrypt an entire drive? VPN SSL IPsec EFS

EFS

Which of the following best describes a certificate authority (CA)? An entity in a PKI that verifies user requests for a digital certificate. An electronic password that allows a person or organization to exchange data securely over the Internet An entity that provides a service used to verify the validity of a digital certificate. An entity that issues digital certificates.

An entity that issues digital certificates.

Which type of cryptanalysis method is based on substitution-permutation networks? Dictionary Linear Differential Integral

Integral

Which of the following is an open-source cryptography toolkit that implements SSL and TLS network protocols and the related cryptography standards required by them? OpenSSL Symantec Drive Encryption EFS BitLocker

OpenSSL

Above all else, which of the following must be protected to maintain the security and benefit of an asymmetric cryptographic solution, especially if it is widely used for digital certificates? Cryptographic algorithm Public keys Private keys Hash values

Private keys

Which of the following is an entity that accepts and validates information contained within a request for a certificate? Validation authority Certificate authority Certificate management system Registration authority

Registration authority

Which of the following is a characteristic of Triple DES (3DES)? Uses 64-bit blocks with 128-bit keys Uses a 168-bit key Is easy to break Uses the Rijndael block cipher

Uses a 168-bit key

Which of the following uses on-the-fly encryption, meaning the data is automatically encrypted immediately before it is saved and decrypted immediately after it is loaded? VeraCrypt Transport Layer Security (TSL) BitLocker Secure Sockets Layer (SSL)

VeraCrypt

Kathy doesn't want to purchase a digital certificate from a public certificate authority, but needs to establish a PKI in her local network. Which of the follow actions should she take? Enable synchronous encryption in her network. Ensure all HTTP traffic uses port 443. Create a local CA and generate a self-signed certificate. Request a certificate from GoDaddy

Create a local CA and generate a self-signed certificate.

Mary is using asymmetric cryptography to send a message to Sam so that only Sam can read it. Which of the following keys should she use to encrypt the message? Mary's public key Mary's private key Sam's public key Sam's private key

Sam's public key

Which of the following is considered an out-of-band distribution method for private key encryption? Sending a secured email. Using a private fiber network. Copying the key to a USB drive. Using a key distribution algorithm.

Copying the key to a USB drive.

Mary wants to send a message to Sam. She wants to digitally sign the message to prove that she sent it. Which of the following cryptographic keys would Mary use to create the digital signature? Mary's public key Sam's private key Mary's private key Sam's public key

Mary's private key

Which of the following is the number of keys used in symmetric encryption? One Two Four Five

One

Bob encrypts a message using a key and sends it to Alice. Alice decrypts the message using the same key. Which of the following types of encryption keys is being used? Digital signature Block cipher Symmetric Asymmetric

Symmetric

Which of the following forms of cryptography is best suited for bulk encryption because of its speed? Asymmetric cryptography Public key cryptography Symmetric cryptography Hashing cryptography

Symmetric cryptography

Donna is configuring the encryption settings on her email server. She is given a choice of encryption protocols and has been instructed to use the protocol that has the most improvements. Which of the following cryptographic protocols should she choose? SSL OpenSSL VeraCrypt TLS

TLS

Which of the following best describes a feature of symmetric encryption? Uses only one key to encrypt and decrypt data. Does not work well for bulk encryption of less sensitive data. Does not require the exchange of the shared secret key. Uses only one algorithm type.

Uses only one key to encrypt and decrypt data.

Which of the following cryptographic algorithms is used in asymmetric encryption? Blowfish Twofish AES Diffie-Hellman

Diffie-Hellman

Alan wants to implement a security tool that protects the entire contents of a hard drive and prevents access even if the drive is moved to another system. Which of the following tools should he choose? VPN EFS IPsec BitLocker

BitLocker

You work for a company that is implementing symmetric cryptography to process payment applications such as card transactions where personally identifiable information (PII) needs to be protected to prevent identity theft or fraudulent charges. Which of the following algorithm types would be best for transmitting large amounts of data? Stream Steganography Cryptanalysis Block

Block

Which of the follow is a characteristic of Elliptic Curve Cryptography (ECC)? Is suitable for small amounts of data and small devices, such as smartphones. Is used to sign a certificate using a private key and to verify a certificate using a public key. Uses multiplication of large prime numbers. Uses symmetric encryption.

Is suitable for small amounts of data and small devices, such as smartphones.

Which of the following is the most frequently used symmetric key stream cipher? Blowfish Ron's Cipher v5 (RC5) Ron's Cipher v4 (RC4) Advanced Encryption Standard (AES)

Ron's Cipher v4 (RC4)

Which of the following is the number of keys used in asymmetric (public key) encryption? One Two Three Four

Two

Which of the following describes a PKI? Software that manages an organization's certificates. A protocol that defines secure key exchange. An algorithm for encrypting and decrypting data. A security architecture that ensures data connections between entities are validated and secure.

A security architecture that ensures data connections between entities are validated and secure.

Which of the following cryptography attacks is characterized by the attacker making a series of interactive queries and choosing subsequent plain texts based on the information from the previous encryption? Chosen ciphertext Known plain text Adaptive chosen plain text Chosen plain text

Adaptive chosen plain text

Robert, an IT administrator, is working for a newly formed company. He needs a digital certificate to send and receive data securely in a Public Key Infrastructure (PKI). Which of the following requests should he submit? He must send identifying data with his certificate request to a registration authority (RA). He must send the MAC and IP addresses with his certificate to a root certificate authority (CA). He must send identifying data and a private key request to a validation authority (VA). He must send identifying data and the encryption algorithm he will use with his certificate request to a certificate authority (CA).

He must send identifying data with his certificate request to a registration authority (RA).

Which of the following terms is the encrypted form of a message that is unreadable except to its intended recipient? plain text encryption algorithm ciphertext steganography

ciphertext

Which of the following cryptography attacks is characterized by the attacker having access to both the plain text and the resulting ciphertext, but does not allow the attacker to choose the plain text? Chosen ciphertext Known plain text Chosen plain text Brute force

Known plain text

Which of the following best explains why brute force attacks are always successful? They test every possible valid combination. They are fast. They are platform-independent. They can be performed in a distributed parallel processing environment.

They test every possible valid combination.

Which of the following is a characteristic of the Advanced Encryption Standard (AES) symmetric block cipher? Uses the Rijndael block cipher. Is used by Pretty Good Privacy (PGP) email encryption. Is easy to break. Uses up to 16 rounds of substitution and transposition.

Uses the Rijndael block cipher.