Pre-Assessment Intro to Cryptography - D334

A business wants to use keys issued by a trusted third party to demonstrate to potential customers that it is a legitimate organization. Which key is used to sign the certificate issued to the business?

A. Private key of the root CA

B. Public key of the root CA

C. Private key of the company

D. Public key of the company

Private key of the root CA

A business wants to use keys issued by a trusted third party to demonstrate it is a legitimate organization to potential customers. Which key should the business send to potential customers to prove its identity?

A. Private key of the root CA

B. Public key of the root CA

C. Private key of the company

D. Public key of the company

Public key of the company

What should an administrator use to import and export all items written using X.509 that are part of a chain of trust?

A. CER

B. Public Key Cryptography Standard (PKCS) #7

C. Public Key Cryptography Standard (PKCS) #12

D. RTF

Public Key Cryptography Standard (PKCS) #12

Which field displays the hash, or digest, of the certificate in an X.509 certificate?

A. Subject

B. Issuer

C. Version

D. Thumbprint

Thumbprint

Which certificate management process involves key recovery?

A. Initialization

B. Issued

C. Cancellation

D. Hold

Issued

Which task does a root CA perform before publishing its own certificate?

A. Encrypting it with its private key

B. Encrypting it with its public key

C. Signing it with its private key

D. Signing it with its public key

Signing it with its private key

Which algorithm is used to generate the thumbprint of a certificate?

A. RSA

B. 3DES

C. AES

D. SHA-1

SHA-1

Large volumes of plaintext need to be encrypted, and the encryption keys need to be securely distributed. Which approach should be used for encryption and distribution?

A. Encrypt by using symmetric keys and distribute by using asymmetric keys

B. Encrypt by using asymmetric keys and distribute by using symmetric keys

C. Encrypt by using symmetric keys and distribute by using symmetric keys

D. Encrypt by using asymmetric keys and distribute by using asymmetric keys

Encrypt by using symmetric keys and distribute by using asymmetric keys

What is the role of a key in asymmetric encryption and decryption?

A. A public key is used for both encryption and decryption.

B. A private key is used for both encryption and decryption.

C. A public key is used for encryption, and a private key is used for decryption.

D. A private key is used for encryption, and a public key is used for decryption.

A public key is used for encryption, and a private key is used for decryption.

A security analyst is validating the integrity and authenticity of a data transaction. Which PKI component is being used?

A. Digital certificate

B. Digital signature

C. Asymmetric encryption

D. Symmetric encryption

Digital signature

Which PKI component generates digital certificates?

A. Certificate signing request (CSR)

B. Certificate policy (CP)

C. Certificate revocation list (CRL)

D. Certificate authority (CA)

Certificate authority (CA)

What is the maximum length (in bits) of encryption keys used by the WEP protocol?

A. 40

B. 56

C. 128

D. 256

40

What is a difference between WPA-Enterprise and WPA-Personal?

A. Support for Temporal Key Integrity Protocol

B. Support for an authentication server

C. Use of a session key

D. Use of a 48-bit initialization vector

Support for an authentication server

Which cipher is used with WEP?

A. RC5

B. RC4

C. TKIP

D. AES

RC4

How does TKIP improve WPA over WEP?

A. Hashes the initialization vector and secret key

B. Implements a RADIUS server

C. Implements an authentication server

D. Creates an AES encryption key

Hashes the initialization vector and secret key

An administrator has configured a virtual private network (VPN) connection utilizing IPsec tunnel mode with Encapsulating Security Payload (ESP) between the corporate office and a remote office. Where can the packets be inspected by intrusion detection systems (IDSs) and virus scanners?

A. Only at the headquarters

B. Only at the offsite location

C. At the headquarters and the offsite location

D. Between the headquarters and the offsite location

At the headquarters and the offsite location

Which default port must be open for the IPsec key exchange to be successful?

A. UDP 162

B. TCP 389

C. TCP 465

D. UDP 500

UDP 500

Which protocol indicates the virtual private network (VPN) is using Authentication Header (AH)?

A. 48

B. 50

C. 51

D. 58

51

Which cipher uses a grid to map letters into numeric values?

A. Bifid

B. SHA-1

C. Caesar

D. Vigenère

Bifid

Which cipher uses a five-by-five matrix with nonrepeating characters?

A. Playfair

B. Rail code

C. Pigpen

D. Vigenère

Playfair

What does a frequency analysis attack to break encryption involve?

A. Analyzing ciphertext to identify text variation and comparing the text to standard English characters

B. Performing an exhaustive search to attempt every possible mapping or key

C. Interfering between two parties and sometimes intercepting or modifying data in the communication stream

D. Identifying part of the ciphertext and the corresponding plaintext

Analyzing ciphertext to identify text variation and comparing the text to standard English characters

Which technique should a security analyst use to determine the key length in a Vigenère cipher?

A. Frequency analysis

B. Brute force

C. Kasiski examination

D. Known plaintext

Kasiski examination

What defines a prime number?

A. Only has factors of itself and 1

B. Only has factors of itself and 2

C. Evenly divisible by 3.14

D. Evenly divisible by 10

Only has factors of itself and 1

What is 29 mod 12?

A. 0

B. 3

C. 5

D. 7

5

Which type of cipher is ChaCha?

A. Asymmetric

B. Block

C. Stream

D. Hash

Stream

What is the key size for RC4 with WEP?

A. 40 bits

B. 128 bits

C. 256 bits

D. 512 bits

40 bits

Which symmetric encryption technique uses a 56-bit key size and a 64-bit block size?

A. AES

B. DES

C. 3DES

D. IDEA

DES

Which wireless security standard uses a 128-bit RC4 stream cipher for encrypted communications?

A. WPA

B. WEP

C. VPN

D. GSM

WPA

Employee B sends Employee A an encrypted message. What does Employee A use to decrypt the message from Employee B?

A. Employee A's private key

B. Employee B's private key

C. Employee A's public key

D. Employee B's public key

Employee A's private key

What is an example of a symmetric algorithm?

A. RSA

B. AES

C. SHA

D. MD5

AES

Which two components involved in performing encryption are known to the party that will perform decryption before symmetric encryption is applied? Choose 2 answers.

Cryptographic algorithm

Cryptographic key

Plaintext content

Initialization vector

Nonce value

Cryptographic algorithm

Cryptographic key

Employee A created a secret key and wants to send it to Employee B without any coworkers being able to decrypt the message. Which key needs to encrypt the message?

A. Employee A's public key

B. Employee A's private key

C. Employee B's public key

D. Employee B's private key

Employee B's public key

What happens to the hash of a file if it is rehashed after the first character of the file is changed?

A. The entire hash is different.

B. The beginning of the hash is altered.

C. The hash is unaltered.

D. The hash algorithm is replaced.

The entire hash is different.

What is the length (in bits) of an MD5 hash output?

A. 32

B. 64

C. 128

D. 256

128

How many characters are used in an LM hash password?

14

A Windows credential is identified as follows: user:FDA95FBABC199D22LLD3B435B51876KK:199DDFD4EF0E9CD9KMNC6FE771IL124B8::: What is used to store this password?

A. MD5

B. Bcrypt

C. SHA-512

D. NTLM

NTLM

What is a rainbow table?

A. List of matching usernames and passwords

B. Precompiled list of common words

C. List of commonly used passwords

D. Precompiled list of hash values

Precompiled list of hash values

Which mode encrypts each group with the same key, leaving each group independent of the others?

A. ECB

B. CBC

C. CFB

D. OFB

ECB

Which mode of block encryption results in the same outcome for matching blocks of a plaintext message?

A. Electronic Code Book (ECB)

B. Output feedback (OFB)

C. Cipher block chaining (CBC)

D. Cipher feedback (CFB)

Electronic Code Book (ECB)

How does CBC mode encryption function?

A. Encrypts each block with the same key, where each block is independent of the others

B. Uses an initialization vector (IV) to encrypt the first block, then uses the result of the encryption to encrypt the next block

C. Uses a self-synchronizing stream on the blocks, where the initialization vector (IV) is encrypted and XORed with the data stream

D. Converts from block into stream, then uses a counter value and a nonce to encrypt the data

Uses an initialization vector (IV) to encrypt the first block, then uses the result of the encryption to encrypt the next block

Which encryption mode always produces the same result for the same plaintext?

A. CBC

B. ECB

C. CFB

D. CTR

ECB

Which information protection method has an 80-bit key and operates on 64-bit data blocks?

A. Skipjack

B. IDEA

C. DES

D. Twofish

Skipjack

How many transformation rounds does AES use with a 192-bit key?

A. 10

B. 12

C. 14

D. 16

12

How many transformation rounds does AES use with a 128-bit key?

A. 10

B. 12

C. 14

D. 16

10

Which encryption algorithm did the National Institute of Standards and Technology (NIST) designate as a specification for the encryption of electronic information?

A. IDEA

B. DES

C. 3DES

D. AES

AES

Which attack tries every combination of letters, numbers, and special characters?

A. Rainbow table

B. Birthday

C. Dictionary

D. Brute-force

Brute-force

How does a dictionary attack break a cipher?

A. Factors the prime numbers used within an RSA algorithm

B. Looks for rollover of the same value for an IV

C. Takes a list of the most common words and tries each entry

D. Matches hash values back to the original plaintext

Takes a list of the most common words and tries each entry

A security analyst decrypted a data set with the same key that originally encrypted the data set. Which cryptographic operation did the analyst use?

A. Asymmetric

B. Symmetric

C. Hashing

D. Kerberos

Symmetric

What should be used when large amounts of data need to be encrypted and decrypted for secure storage based on groupings of 128, 192, or 256 bits?

A. Symmetric stream

B. Symmetric block

C. Asymmetric public key

D. Asymmetric private key

Symmetric block

Why is symmetric stream used to encrypt video when speed is a major concern?

A. It signs files and encrypts that hash of the file to verify integrity and authenticity.

B. It encrypts and decrypts data in blocks of characters at a time with a complex algorithm.

C. It encrypts a small amount of information, which is decrypted with a private key.

D. It uses the same key to encrypt and decrypt large amounts of media.

It uses the same key to encrypt and decrypt large amounts of media.

Why should an asymmetric public key be used to encrypt a symmetric key that is being sent to one person?

A. It uses the same key to encrypt and decrypt large amounts of media, one bit at a time.

B. It encrypts and decrypts data in blocks of characters at a time with a complex algorithm.

C. It encrypts a small amount of information, which is decrypted with the corresponding private key.

D. It signs files and encrypts the hash of the file to verify integrity and authenticity.

It encrypts a small amount of information, which is decrypted with the corresponding private key.

Which type of attacks are Diffie-Hellman methods vulnerable to?

A. Man-in-the-middle

B. Brute-force

C. Rainbow

D. Dictionary

Man-in-the-middle

Which mechanism mitigates a copy-and-paste attack when using AES?

A. Electronic Code Book (ECB)

B. Output feedback (OFB) loop

C. Message digest 6 (MD6)

D. Secure Hash Algorithm 1 (SHA-1)

Output feedback (OFB) loop

Which mechanism can be used to ensure perfect forward secrecy during key exchange when using symmetric encryption?

A. MD5

B. ECDSA

C. ECDH

D. SHA-2

ECDH

Which encryption component ensures that the compromise of a long-term key prevents the compromise of any previous session keys?

A. Integrity check

B. Client hello

C. Server hello

D. Forward secrecy

Forward secrecy

What can XOR use as a pseudorandom number to create unique ciphertext?

A. Symmetric key

B. Message digest

C. Permanent password

D. Initialization vector

Uses the results of the IV to encrypt the next block

How does cipher block chaining (CBC) create randomness in a second block after encrypting the first block with an initialization vector (IV)?

A. Uses the results of the IV to encrypt the next block

B. Increments the IV to encrypt the next block

C. Creates a new, random IV to encrypt the next block

D. Generates a new IV to encrypt the next block

Uses the results of the IV to encrypt the next block

How is information about Bitcoin transactions stored?

A. Command and control center

B. Platform as a service in the cloud

C. Infrastructure as a service in the cloud

D. Distributed peer-to-peer network

Distributed peer-to-peer network

What is one of the primary characteristics of a blockchain in the context of Bitcoin?

A. Adding blocks to a blockchain is computationally expensive.

B. The security of the chain in a blockchain is independent of its length.

C. Transactions between each block are chained.

D. Transactions within each block are chained.

Adding blocks to a blockchain is computationally expensive.

What is the length (in bits) of the private key used to sign transactions and associated with an individual wallet in the context of Bitcoin?

A. 64

B. 128

C. 256

D. 512

256