2.8 Summarize the basics of cryptographic concepts.

Question 1

Cipher Text

Answer 1

encrypted message

Question 2

Cipher

Answer 2

Algorithm used to encrypt and/ or decrypt

Question 3

Cryptanalysis

Answer 3

Finding vulnerabilities in ciphers

Question 4

Crypto graphic Key

Answer 4

A KEY added to the end the cipher to encrypt it.

Question 5

Key Stretching

Answer 5

encrypting a key multiple times to strength the key.

Question 6

Bcrypt

Answer 6

Key stretching library

Question 7

PBKDF2

Answer 7

Key stretching library

Question 8

Lightweight cryptography

Answer 8

Used for IoT cryptography that has limited resources to encrypt

Question 9

Homomorphic encryption (HE)

Answer 9

Preform calculations on a algorithm with decrypting the data.

Saves the encrypted result.

Question 10

Symmetric Encryption

Answer 10

(Shared Secret)
Only using one key to decrypt and encrypt data.
If the key becomes known to unauthorized parties then you have to redo your encryption.

Question 11

Asymmetric Encryption

Answer 11

Two or more different keys Public and Private.

Question 12

Private Key and Public Key

Answer 12

Key you only have and a key everyone can see
Both mathematically related

Question 13

EEC

Answer 13

Elliptic curve cryptography

IoT use curves for Asymmetric encryption because they don’t have the computing power for it

Question 14

Digital Signatures

Answer 14

Cryptography/encryption combined with Hashing

Authentication non-repudiation, and integrity

Question 15

Collison

Answer 15

When two hashes have the same out put

Question 16

SHA256

Answer 16

Hash Algorithm

Question 17

Salt

Answer 17

Added data added to a Hash.
Users that have the same password have the same hash. adding Salt combat that

Question 18

Key Length

Answer 18

Longer a Key the stronger the key
Asymmetric 3,072 bit
Symmetric key 128 bit

Question 19

Key exchange

Answer 19

Out-of-band - transfer/sending a key off the Network

In-band - Sending a key on the Network

Question 20

Ephemeral Key

Answer 20

A key that is only used once.

Question 21

PFS

Answer 21

Perfect Forward Secrecy
A system that allows you not be compromised by not using the same key twice ever.
Prevents people from getting your server key.

Question 22

Steganography

Answer 22

Hide code code through a image, audio, video.
Not a true secure message.

Question 23

Quantum Computing

Answer 23

Computing- doesn’t use bit like regular computer. Quantum computing uses Qubits and the value is between 0-1.

Question 24

Post-Quantum

Answer 24

Current Algorithm that we you today for cryptography can be easily solved by quantum computers.

NTRU slows down quantum cryptography

Question 25

Quantum Communication or
QKD

Answer 25

Quantum Key Distribution-
Creates unbreakable encryption that you can send in the network without being decrypted.

If there is eavesdropping the key would authenticate.

Question 26

Stream Ciphers

Answer 26

Encrypts one bit/byte at a time
Symmetric encryption

Question 27

Block Cipher

Answer 27

Encrypts a entire block
if there isn’t a enough data the data will be added to make a 64 byte (Padding)

Question 28

Modes of Operation

Question 29

ECB

Answer 29

Electronic Code Book
uses a single Encryption key and uses that for each identical plaintext block encryption

Question 30

CBC

Answer 30

Cipher Clock Chaining

Right before Plaintext block is “keyed” a IV (initialization vector) is added before hand.
After that the cipher block is then used in the same place as the IV.
This allows randomization

Question 31

CTR

Answer 31

Counter or Counter Mode
Top: Unencrypted Counter
Second: Key
Third: Plaintext added to the block
Bottom: Cipher Text

Question 32

GCM

Answer 32

Galois/Counter Mode
Adding authentication the mode of operation

Question 33

Block Chain

Answer 33

A list of records, when something is added it is done by a cryptographic algorithm

Resistant to modification