Cryptography

Question 1

What is X.509?

Answer 1

A Standard that Defines the Format of PKI (Public Key Infrastructure) digital certificates.

Question 2

What technology is NOT PKI x.509 compliant and cannot be used in various secure functions?
1. AES
2. PKCS
3. Blowfish
4. SSL/TLS

Answer 2

3. Blowfish

Question 3

What does PKCS stand for?

Answer 3

Public Key Cryptography Standard

Question 4

What is Asymmetric Encryption?

Answer 4

Uses Public and Private Key pairs.

Question 5

What is Symmetric Encryption?

Answer 5

Single/Shared Key.

Question 6

What is Elliptic curve cryptography (ECC) encryption best used for?

Answer 6

Mobile devices.

Question 7

How many bits does MD5 (Message Digest algorithm) produce?

Answer 7

128 bits.

Question 8

How many bits does SHA-1 produce?

Answer 8

160 bits

Question 9

How many bits does SHA-2 produce?

Answer 9

Has 4 functions, outputs are 224, 256, 384 and 512 bits.

Question 10

How many bits does NTLM produce?

Answer 10

NTLM creates a 128-bit fixed output.

Question 11

What algorithms does Public Key Infrastructure (PKI) use?

Answer 11

RSA 1024 bit

Question 12

What is IKE (Internet Key Exchange)?

Answer 12

Protocol used to setup security associations with IPSEC VPNs.

Question 13

Which encryption type MOST likely is used for securing the key exchange during a client-to-server VPN connection?

Answer 13

ISAKMP
It is used in IPSec, which is commonly used in securing the key exchange during the establishment of a client-to-server VPN connection.

Question 14

How many bits does RIPEMD hash produce?

Answer 14

160 bits

Question 15

How many bits are in the Diffie-Hellman (DH) group 1?

Answer 15

768 bits

Question 16

How many bits are in the Diffie-Hellman (DH) group 2?

Answer 16

1024 bits

Question 17

How many bits are in the Diffie-Hellman (DH) group 5?

Answer 17

1536 bits

Question 18

How many bits are in the Diffie-Hellman (DH) group 14?

Answer 18

2048 bits

Question 19

How many bits are in the Diffie-Hellman (DH) group 15?

Answer 19

3072 bits

Question 20

What is a FREAK attack in SSL?

Answer 20

Type of Downgrade attack to force RSA to use weaker length.

Question 21

What is a POODLE attack in SSL?

Answer 21

Downgrade from TLSv1.0 to SSLv3.0 to decrypted communication.

Question 22

What is a DROWN attack in SSL?

Answer 22

Decryption vulnerability in SSLv2.0

Question 23

What is a Replay Attack?

Answer 23

Used for MITM attack, communication is maliciously or fraudulently repeated or delayed by the attacker.

Question 24

What is key escrow?

Answer 24

Cryptographic key exchange process in which a key is held in escrow, or stored, by a third party

Question 25

In this cryptography attack method, the cybercriminal makes a series of interactive queries, choosing subsequent plaintexts based on the information from the previous encryptions?

Answer 25

Adaptive chosen-plaintext attack