Section 2.8 Basics of Cryptographic concepts

Question 1

What do you call the conversion of machine-readable and human-readable communicated information into an unreadable form that keeps the information confidential and private?

Answer 1

Cryptography

Question 2

The central function of cryptography is _________, the transformation of data into an unreadable form.

Answer 2

Encryption

Question 3

Encryption ensures _______ by keeping the information hidden from those for whom the information is not intended.

Answer 3

Confidentiality

Question 4

What transforms encrypted data back into an intelligible form?

Answer 4

Decryption

Question 5

Cryptography also supports ________ by making systems better able to handle resource constraints.

Answer 5

High resiliency

Question 6

Cryptographic algorithms and techniques are chosen based on?

Answer 6

The level of protection required and resource constraints

Question 7

The number of bits that are within an encryption algorithm’s key is?

Answer 7

Key length/size

Question 8

The set of all possible permutations of a key is the?

Answer 8

Keyspace

Question 9

Data integrity is maintained by using what cryptologic function?

Answer 9

Hashing

Question 10

What is often used to create signatures for files that indicate whether a file has been tampered with?

Answer 10

Hashing

Question 11

What cryptologic function is used to maintain Authentication?

Answer 11

Encrypted digital certificates are used to identify users electronically on a network

Question 12

By implementing _____________ processes, a cryptographic system can be considered secure for business and legal transactions?

Answer 12

Nonrepudiation

Question 13

What concept provides security by modifying the data to make it unreadable to a human or program trying to use it?

Answer 13

Obfuscation

Question 14

A system that provides encryption and decryption services is called a?

Answer 14

Cryptosystem

Question 15

A cryptosystem uses a mathematical encryption ___________ to turn data into ciphertext?

Answer 15

Algorithm/Cipher

Question 16

A _______ is like a password that’s combined with an algorithm to create the ciphertext.

Answer 16

key

Question 17

The strength of an encryption key depends on the algorithm’s what?

Answer 17

keyspace

Question 18

Most attacks on encryption center on what?

Answer 18

The interception of keys

Question 19

What concept means that the outcome of the ciphertext is dependent on several parts of the key, rather than only one? This concept increases the change in the plaintext to ciphertext.

Answer 19

Confusion

Question 20

What concept means that even a small change in the plaintext results in a significant change in the ciphertext?

Answer 20

Diffusion

Question 21

What type of cipher switches out the plaintext characters with other characters?

Answer 21

Substitution Cipher

Question 22

What type of cipher rearranges the characters in different places through mathematical formulas?

Answer 22

Transposition Cipher

Question 23

What encryption scheme has both parties using the same key to encrypt and decrypt?

Answer 23

Symmetric Encryption/Secret Key

Question 24

The security of Symmetric Encryption depends on?

Answer 24

Users keeping their keys private

Question 25

A symmetric systems is much faster than asymmetric encryption because what?

Answer 25

The underlying algorithms are simpler and more efficient.

Question 26

What type of symmetric encryption encrypts data one bit at a time?

Answer 26

Stream Ciphers

Question 27

What is the most commonly found streaming cipher, found in the Wired Equivalent Privacy (WEP) protocol?

Answer 27

RC4

Question 28

What type of symmetric encryption encrypts entire blocks of data?

Answer 28

Block Ciphers

Question 29

What do you call authentication schemes that have been developed to work with block ciphers to provide not only encryption but also authentication?

Answer 29

Authenticated models of operation/Authenticated encryption

Question 30

What encryption scheme uses 2 mathematically-related, different keys to encrypt and decrypt?

Answer 30

Asymmetric Encryption scheme

Question 31

What encryption concept involves a 3rd party, such as a government agency or an authorized organization, that holds a special third key used to encrypt the private key, which is then stored in a secure location?

Answer 31

Key escrow

Question 32

The advantage of an asymmetric scheme over symmetric schemes is that it offers a level of?

Answer 32

Authentication and Nonrepudiation

Question 33

What kind of cryptosystem uses complex mathematical structures to create secure asymmetric algorithms and keys? Often used as a lightweight solution, provides functionality such as encryption an digital signatures.

Answer 33

Elliptic-curve Cryptography (ECC)

Question 34

What kind of key exchange takes places within the normal communication channel?

Answer 34

In-band key exchange

Question 35

what kind of key exchange utilizes a separate channel outside the norm to authenticate the user?

Answer 35

Out-of-band Key exchange

Question 36

What do you call temporary keys that are made each time a key is needed and are temporary in nature?

Answer 36

Ephemeral Keys

Question 37

What is designed by using complex cryptographic protocols to prevent the situation where a compromise of one secret key or message leads to a compromise of previous confidential messages?

Answer 37

Perfect Forward Secrecy (PFS)

Question 38

What do you call a randomly generated input often used in hashing?

Answer 38

Salt

Question 39

What do you call a one-time use number that are randomly created to ensure if the same message is encrypted twice then the outcomes are different?

Answer 39

Initialization Vector (IV)

Question 40

What do you call numbers that are used once for a limited time?

Answer 40

Nonces

Question 41

What are the difference between nonces and IV's?

Answer 41

IV's are random

Question 42

What do you call the process of taking a weak key and making it stronger against attacks by creating an enhanced key; an initial key and hash function or block cipher applied in a loop?

Answer 42

Key stretching

Question 43

What kind of cryptography uses light waves pulsing over fiber optic cable to transmit code which shares the key between two users?

Answer 43

Quantum Cryptography

Question 44

What kind of encryption encrypts data while it is being processed? It also allows for computation to take place on ciphertext, with a result that matches what the value of the plaintext would have been if not encrypted.

Answer 44

Homomorphic Encryption

Question 45

What concept refers to algorithms, generally asymmetric, that are considered secure against attacks using quantum computing?

Answer 45

Post-Quantum Computing

Question 46

What is the concept of hiding data in other media such as graphic images, digital audio, or video files?

Answer 46

Steganography

Question 47

What do you call publicly accessible ledgers that record online transactons?

Answer 47

Blockchains

Question 48

What prevent messages from being modified in transit?

Answer 48

Hashing algorithms

Question 49

What do you call a mathematical function that takes a variable-sized message and transforms it into a fixed-length value? Difficult to reverse and the results are never decrypted.

Answer 49

One-way Hash

Question 50

What do you call the output of a one-way hash?

Answer 50

Hash Value/Message Digest

Question 51

Attacks against one-way hash functions can be prevented by using?

Answer 51

longer hash values

Question 52

What occurs when 2 different hash messages result in the same hashing value?

Answer 52

Hash value collisions

Question 53

What attack occurs when an attacker intercepts a hash and uses it to authenticate directly, rather than using the underlying plaintext password?

Answer 53

Pass the Hash Attack

Question 54

What is created when the digest of the message is encrypted using the sender's private key?

Answer 54

Digital signature

Question 55

What hash produces a 128-bit hash value used for security applications and integrity checking?

Answer 55

MD5

Question 56

What do you call a key agreement protocol that enables users to exchange encryption keys over an insecure medium?

Answer 56

Diffie-Hellman Exchange (DHE)

Question 57

What key agreements allow the two parties to authenticate each other through the addition of more advanced technologies and is used in the Public Key Infrastructure?

Answer 57

Elliptic-curve Diffie-Hellman Exchange (ECDHE)

Question 58

What asymmetric algorithm is used for both digital signatures and general encryption? Widely used in open standards and cryptosystems, including PGP and GPG.

Answer 58

ElGamal

Question 59

What is the digital authentication standard of the US Government?

Answer 59

Digital Signature Algorithm (DSA)

Question 60

What do you call an encrypted hash value used to ensure the identity and integrity of a message?

Answer 60

Digital signature

Question 61

What guarantees the individual sending the message is who he claims to be?

Answer 61

Digital signature

Question 62

What is the hash function message digest originally based on MD4?

Answer 62

RIPEMD

Question 63

What is used as an algorithm for message authentication purposes, where the authentication is applied using hash functions and a secret key to create an authentication code value?

Answer 63

Hash-based Message Authentication Code (HMAC)

Question 64

Information assurance through encryption protects information and information systems by securing their what?

Answer 64

Confidentiality, integrity, authentication, and nonrepudiation

Question 65

Random numbers are often used within algorithms to prevent?

Answer 65

Replay attacks

Question 66

What do you call a small, fast key that is used for encryption in small mobile devices?

Answer 66

ECC

Question 67

What is a feature of specific key agreement protocols that assures session keys will not be compromised if long-term secrets (private keys) used in session key exchange are compromised?

Answer 67

PFS

Question 68

What indicates that a cryptographic system generates random public keys for each session and it does not use a deterministic algorithm in the process?

Answer 68

PFS

Question 69

What encryption algorithm is typically used for bulk encryption/encrypting large amounts of data?

Answer 69

Symmetric

Question 70

What kind of encryption algorithm is AES256?

Answer 70

Symmetric

Question 71

What encryption algorithm is typically used for the distribution of symmetric bulk encryption keys (shared keys)?

Answer 71

Asymmetric

Question 72

What encryption algorithm is typically used for identity authentication via digital signatures and certificates?

Answer 72

Asymmetric

Question 73

What encryption algorithm is typically used for non-repudiation services and key agreements?

Answer 73

Asymmetric

Question 74

What are typically used for the verification of digital signatures?

Answer 74

Hash functions

Question 75

What are typically used for the generation of pseudo-random numbers?

Answer 75

Hash functions

Question 76

What do you call the practice of harnessing the principles of quantum mechanics to improve security and detect whether a third party is eavesdropping on communications?

Answer 76

Quantum Cryptography

Question 77

What mode of operation for block ciphers is the simplest and least secure mode? Processes 64-bit blocks, encrypts blocks with the chosen key.

Answer 77

Electronic Codebook Mode (ECB)

Question 78

What mode of operation for block ciphers has each block of unencrypted text XORed with the block of ciphertext immediately preceding?

Answer 78

Cipher Block Chaining (CBC)

Question 79

What mode of operation for block ciphers uses an incrementing counter instead of a seed? Errors do not propagate.

Answer 79

Counter (CTR)

Question 80

What is the go to option for encryption for low power small devices?

Answer 80

ECC (Asymmetric)

Question 81

What is the go to option for encryption for the military?

Answer 81

AES 256 (Symmetric)

Question 82

What kind of encryption allows users to run calculations on data while it is still encrypted?

Answer 82

Homomorphic Encryption

Question 83

What kind of encryption allows data to be encrypted and out-sourced to commercial clouds for processing?

Answer 83

Homomorphic Encryption

Question 84

Low power devices often use _________ for encryption, as it uses a small key.

Answer 84

ECC

Question 85

What should be used to check/support file integrity?

Answer 85

File Hash

Question 86

What can be used to ensure integrity for email?

Answer 86

Digital signatures