Domain 3: Cryptography

Question 1

Science of breaking encrypted messages to recover their meaning

Answer 1

Cryptanalysis

Question 2

• Always hides the true meaning of a message

- Converts messages from plaintext to ciphertext

Answer 2

Cipher

Question 3

Unencrypted message

Answer 3

Plaintext

Question 4

Converts plaintext to ciphertext

Answer 4

Encryption

Question 5

Turns ciphertext back into plaintext

Answer 5

Decryption

Question 6

• Random number that acts as a placeholder variable in mathematical function.
• When function is executed, this item is replaced with a random number generated at the moment of processing for one-time use

Answer 6

Nonce

Question 7

• Historical cipher

- To encrypt a message, you shift each letter of the alphabet three places to the right

Answer 7

Caesar Cipher

Question 8

• Historical cipher
• A machine that used a series of three to six rotors to implement a extremely complicated substitution cipher
• Used by Germans on WWI

Answer 8

Enigma

Question 9

• Historical cipher

- Machine used by Japanese in WWII for cryptosystems

Answer 9

Purple Machine

Question 10

Out of the CIA triad what does cryptography provide?

Answer 10

Confidentiality and Integrity

Question 11

The order of the plaintext should be dispersed in the ciphertext

Answer 11

Diffusion

Question 12

The relationship between the plaintext and ciphertext should be as random as possible

Answer 12

Confusion

Question 13

Use an encryption algorithm to replaces each character of the plaintext with another character

Answer 13

Cryptographic Substitution

Question 14

Use an encryption algorithm to rearrange the characters of the plaintext, forming the ciphertext message

Answer 14

Permutation aka Transposition

Question 15

• Key must be generated randomly without any known pattern
• Key must be at least long as the message to be encrypted
• Key must be used one time then discarded

Answer 15

One-Time Pads

Question 16

In this cipher, the encryption key is as long as the message itself and is often chose from a common book (i.e. Moby Dick)

Answer 16

Running Key Cipher

Question 17

Describes how long it will take to break a cryptosystem (decrypt a ciphertext without the key)

Answer 17

Work factor

Question 18

Uses one alphabet, in which a specific letter substitutes for another

Answer 18

Monoalphabetic cipher

Question 19

• Uses multiple alphabets

- i.e. Vigenere cipher

Answer 19

Polyalphabetic cipher

Question 20

Logical functions that returns a true value when only one of the input values is true

Answer 20

Exclusive OR (XOR)

Question 21

Process of selecting the right method (i.e. cipher) and implementation for the right job, typically organization-side scale.

Answer 21

Cryptographic Protocol Governance

Question 22

• Key agreement algorithm

- Use discrete logarithms

Answer 22

Diffie-Hellman

Question 23

• Part of the 3 major public key cryptosystems
• Uses discrete logarithms
• Extension of Diffie Hellman key exchange algorithm that depends on modular arithmetic

Answer 23

ElGamal

Question 24

Linux systems use _____ to encrypt passwords and this is based on ______.

Answer 24

bcrypt

Blowfish

Question 25

- Cryptographic systems of symbols that represent words or phrases, are sometimes secret, but don’t necessarily provide confidentiality - i.e. “10-4” used by law enforcement

Answer 25

Codes

Question 26

- Communication concept specific type of info is exchanged, but no real data is transferred - i.e. Digital signatures and digital certificates

Answer 26

Zero-knowledge proof

Question 27

- Info or privilege required to perform an operation is divided among multiple users - Ensures no one person has sufficient privileges to compromise the security of the environment - i.e. M of N Control

Answer 27

Split knowledge

Question 28

Requires that a min number of agents (M) out of a total number of agents (N) work together to perform high-security tasks

Answer 28

M of N Control

Question 29

What are the three main methods used to exchange secret keys securely?

Answer 29

1. Offline distribution 2. Public key encryption 3. Diffie-Hellman exchange algorithm

Question 30

- Part of the 3 major public key cryptosystems | - Depends on the difficulty of factoring the product of prime numbers

Answer 30

RSA

Question 31

Name the 3 major public key cryptosystems for Asymmetric encryption?

Answer 31

1. RSA 2. ElGamal 3. Elliptic Curve Cryptography (ECC)