Chapter 1

Question 1

What is used to encrypt individual files?

Answer 1

Aescrypt

Question 2

What is used to encrypt full disks?

Answer 2

Bitlocker or FileVault

Question 3

What is One-time pad?

Answer 3

is considered to be unbreakable since it only uses its cipher code once.

Question 4

PRNG (Pseudo-Random Number Generator)

Answer 4

This method repeats random numbers after a given time. They are fast and are also deterministic and are useful in producing a repeatable set of random numbers.

Question 5

Frequency Analysis

Answer 5

is a cipher cracking methodology that involves identifying patterns and variations in the probability of codes.

Question 6

Entropy

Answer 6

relates to the degree of uncertainty of the encryption process.

Question 7

Hardware and Software encryption

Answer 7

Hardware encryption is more efficient than software encryption.

Question 8

HSM (Hardware Security Module)

Answer 8

is a tamper-evident and intrusion resistant physical device that safeguards and manages cryptographic keys and provides cryptographic processing.

Question 9

TPM Trusted Platform Module

Answer 9

is a dedicated processor that handles hardware-level encryption; allows the use of full disk encryption on a hard drive in a manner that minimizes the impact on system performance. TPM contains the encryption keys.

Question 10

Enigma Machine

Answer 10

Used a polyalphabetic substitution cipher, which did not repeat within a reasonable time period, along with a secret key. For the cracking of the Enigma cipher, the challenge was thus to determine both the algorithm and secret key.

Question 11

Combinations

Answer 11

not concerned with the order

Question 12

Permutations

Answer 12

all options considered including sequence

Question 13

Diffie-Hellman

Answer 13

key exchange algorithm used to exchange the secret key in symmetric cryptography

Question 14

Common block cipher modes

Answer 14

ECB, CBC, CFB, OFB, and CTR.

Question 15

CFB, OFB, and CTR allow the block cipher to operate like a stream cipher.

Answer 15

CFB, OFB, and CTR allow the block cipher to operate like a stream cipher.

Question 16

Hashing

Answer 16

describes One-Way or irreversible encryption used for protecting the integrity of data.

Question 17

Hashing involves

Answer 17

taking a VARIABLE length input and producing a FIXED length output (message digest)

Question 19

Similar context/ Pre-image attack

Answer 19

Part of the message has some significance to the original and generates the same hash signature.

Question 20

2 Main applications of Public Key

Answer 20

Identity checking and key protection

Question 21

RSA

Answer 21

has a heavy overhead on processor loading and is not well suited to embedded systens

Question 22

Bitcoin

Answer 22

uses ECC (Elliptic Curve cryptography) with a 32-byte private keys and 64 byte public keys.

Question 23

El Gamal

Answer 23

is a public key method that is used in both encryption and digital signing.