C839 INTRODUCTION TO CRYPTOGRAPHY QUESTIONS
AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS)
|ALREADY GRADED A+||BRAND NEW
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?
Ans✓✓✓ 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?
Ans✓✓✓ 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? Ans✓✓✓ Public Key
Cryptography Standard (PKCS) #12
Which field displays the hash, or digest, of the certificate in an X.509
certificate? Ans✓✓✓ Thumbprint
Employee B sends Employee A an encrypted message.What does
Employee A use to decrypt the message from Employee B? Ans✓✓✓
Employee A's private key
What is an example of a symmetric algorithm? Ans✓✓✓ 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. Ans✓✓✓ 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? Ans✓✓✓ Employee B's public key
Which mode encrypts each group with the same key, leaving each group
independent of the others? Ans✓✓✓ Electronic Code Book (ECB)
Which mode of block encryption results in the same outcome for
matching blocks of a plaintext message? Ans✓✓✓ Electronic Code
Book (ECB)
How does CBC mode encryption function? Ans✓✓✓ 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? Ans✓✓✓ Electronic Code Book (ECB)
Which information protection method has an 80-bit key and operates on
64-bit data blocks? Ans✓✓✓ Skipjack
,How many transformation rounds does AES use with a 192-bit key?
Ans✓✓✓ 12
How many transformation rounds does AES use with a 128-bit key?
Ans✓✓✓ 10
Which encryption algorithm did the National Institute of Standards and
Technology (NIST) designate as a specification for the encryption of
electronic information? Ans✓✓✓ AES
What is the length (in bits) of an MD5 hash output? Ans✓✓✓ 128
How many characters are used in an LM hash password? Ans✓✓✓ 14
A Windows credential is identified as follows:
user:FDA95FBABC199D22LLD3B435B51876KK:199DDFD4EF0E9C
D9KMNC6FE771IL124B8:::
What is used to store this password? Ans✓✓✓ NTLM
What is a rainbow table? Ans✓✓✓ Precompiled list of hash values
Which type of cipher is ChaCha? Ans✓✓✓ Stream
, What is the key size for RC4 with WEP? Ans✓✓✓ 40 bits
Which symmetric encryption technique uses a 56-bit key size and a 64-
bit block size? Ans✓✓✓ DES
Which wireless security standard uses a 128-bit RC4 stream cipher for
encrypted communications? Ans✓✓✓ WPA
A security analyst decrypted a data set with the same key that originally
encrypted the data set. Which cryptographic operation did the analyst
use? Ans✓✓✓ 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? Ans✓✓✓ Symmetric block
Why should an asymmetric public key be used to encrypt a symmetric
key that is being sent to one person? Ans✓✓✓ 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?
Ans✓✓✓ Man-in-the-middle
AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS)
|ALREADY GRADED A+||BRAND NEW
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?
Ans✓✓✓ 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?
Ans✓✓✓ 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? Ans✓✓✓ Public Key
Cryptography Standard (PKCS) #12
Which field displays the hash, or digest, of the certificate in an X.509
certificate? Ans✓✓✓ Thumbprint
Employee B sends Employee A an encrypted message.What does
Employee A use to decrypt the message from Employee B? Ans✓✓✓
Employee A's private key
What is an example of a symmetric algorithm? Ans✓✓✓ 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. Ans✓✓✓ 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? Ans✓✓✓ Employee B's public key
Which mode encrypts each group with the same key, leaving each group
independent of the others? Ans✓✓✓ Electronic Code Book (ECB)
Which mode of block encryption results in the same outcome for
matching blocks of a plaintext message? Ans✓✓✓ Electronic Code
Book (ECB)
How does CBC mode encryption function? Ans✓✓✓ 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? Ans✓✓✓ Electronic Code Book (ECB)
Which information protection method has an 80-bit key and operates on
64-bit data blocks? Ans✓✓✓ Skipjack
,How many transformation rounds does AES use with a 192-bit key?
Ans✓✓✓ 12
How many transformation rounds does AES use with a 128-bit key?
Ans✓✓✓ 10
Which encryption algorithm did the National Institute of Standards and
Technology (NIST) designate as a specification for the encryption of
electronic information? Ans✓✓✓ AES
What is the length (in bits) of an MD5 hash output? Ans✓✓✓ 128
How many characters are used in an LM hash password? Ans✓✓✓ 14
A Windows credential is identified as follows:
user:FDA95FBABC199D22LLD3B435B51876KK:199DDFD4EF0E9C
D9KMNC6FE771IL124B8:::
What is used to store this password? Ans✓✓✓ NTLM
What is a rainbow table? Ans✓✓✓ Precompiled list of hash values
Which type of cipher is ChaCha? Ans✓✓✓ Stream
, What is the key size for RC4 with WEP? Ans✓✓✓ 40 bits
Which symmetric encryption technique uses a 56-bit key size and a 64-
bit block size? Ans✓✓✓ DES
Which wireless security standard uses a 128-bit RC4 stream cipher for
encrypted communications? Ans✓✓✓ WPA
A security analyst decrypted a data set with the same key that originally
encrypted the data set. Which cryptographic operation did the analyst
use? Ans✓✓✓ 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? Ans✓✓✓ Symmetric block
Why should an asymmetric public key be used to encrypt a symmetric
key that is being sent to one person? Ans✓✓✓ 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?
Ans✓✓✓ Man-in-the-middle
