Cryptography

Question 1

the practice of disguising information in a way that looks random

Answer 1

Cryptography

Question 2

earliest known and simplest cypher; uses substitution and a decoder ring

Answer 2

Caesar Cipher

Question 3

breaking encrypted codes

Answer 3

Cryptanalysis

Question 4

employees the Caesar cipher as one element of the encryption process; requires a key

Answer 4

Vingenere Cipher

Question 5

Classic cryptography components (two)

Answer 5

Algorithm and key for encryption

Question 6

encoded and decoded with the same key; The primary way that we encrypt data

Answer 6

symmetric encryption

Question 7

sending key with encrypted data

Answer 7

in-band

Question 8

sending key without encrypted data

Answer 8

out-of-band

Question 9

uses a key pair (public and private)

Answer 9

Asymmetric encryption

Question 10

defines key properties, communication requirements for the key exchange and the actions taken through encryption and decryption process

Answer 10

Cryptosystem

Question 11

Which algorithm is a block cipher, has 64-bit block size, 16 rounds, and a key size of 56 bits?

Answer 11

Data Encryption Standard (DES)

Question 12

Which algorithm has a 64-bit block size and a key size of 32-448 bits?

Answer 12

Blowfish

Question 13

Which algorithm has a 64-bit block size and a 168 bit key size?

Answer 13

Triple DES

Question 14

Which algorithm is the U.S. government encryption standard supported by the NIST and has a 128-bit block size and a key size of 128,192,or 256 bits?

Answer 14

Advanced Encryption Standard (AES)

Question 15

What type of algorithm encrypts one bit at a time?

Answer 15

Streaming cipher

Question 16

a fixed size input to a cryptographic primitive that is typically required to be random or pseudorandom

Answer 16

Initialization vector

Question 17

outputs true only when inputs differ (one is true, zero is false)

Answer 17

Exclusive OR (XOR)

Question 18

each block of plaintext is XORed with the previous cipher text block before being encrypted; each cipher text block depends on all plaintext blocks processed up to that point. To make each message unique, an initialization vector

Answer 18

Cipher Block Chaining (CRB)

Question 19

makes a block cipher into self-synchronizing stream cipher. almost identical to CBC performed in reverse

Answer 19

Cipher Feedback (CFB)

Question 20

makes a block cipher into a synchronous stream cipher; generates keystream blocks, which are XORed with the plaintext blocks to get the cipher text

Answer 20

Output Feedback

Question 21

generates the next keystream block by encrypting successive values of a “counter.” The counter can be any function which produces a sequence which is guaranteed not to repeat for a long time, although an actual increment-by-one counter is simplest and most popular.

Answer 21

Counter (CTR)

Question 22

The message is divided into blocks, and each block encrypted separately.

Answer 22

Electronic Codebook (ECB)

Question 23

plain text converted into 16-bit, 64-bit, or 128-bit binary cipher text

Answer 23

binary block

Question 24

o Asymmetric cryptographic algorithm
o Based on the fact that finding the factors of a large composite number is difficult: when integers are prime numbers, the problem is called prime factorization

Answer 24

RSA Alogrithm

Question 25

An approach to public-key cryptography based on the algebraic structure of elliptic curves over finite fields

Answer 25

Elliptic Curve Cryptography (ECC)

Question 26

o Doesn’t provide encryption, provides a methodology for two parties to come up with the same key
o Key agreement (or exchange) protocol
o Groups help by defining the size or the structure of the key to use
o Can have very large keys

Answer 26

Diffie Hellman

Question 27

Encrypts a message with the public key; the message is decrypted with the private key

Answer 27

Pretty Good Privacy (PGP)

Question 28

Decentralized trust model that Establishes the authenticity between a public key and its owner

Answer 28

web of trust

Question 29

o Provides integrity when it comes to the CIA of security

o Does not encrypt data but it gives it integrity

Answer 29

Hashing

Question 30

128 bit hash invented by Ron Rivest in 1992

Answer 30

Message Digest 5 (MD5)

Question 31

Hash developed by NIS. Has a 160 bit hash, 256 bit hash, 512 bit hash version

Answer 31

Secure Hash Algorithm (SHA)

Question 32

hash algorithm with 128, 160, 256, 320 bit digests

Answer 32

RIPEMD (RACE Integrity Primitives Evaluation Message Digest)

Question 33

occurs when two distinct pieces of data have the same hash value, checksum, fingerprint, or cryptographic digest

Answer 33

Collision

Question 34

Specific type of message authentication code (MAC) involving a cryptographic hash function and a secret cryptographic key

Answer 34

HMAC (hash-based message authentication code)

Question 35

the process of taking data and hiding it in other data

Answer 35

Steganography

Question 36

At minimum, what does a digital certificate contain?

Answer 36

public key, digital signature

Question 37

What can you add to a digital certificate to make it more secure?

Answer 37

A third party digital signature

Question 38

What is a digital certificate that ONLY contains a public key and digital signature called?

Answer 38

Unsigned certificate

Question 39

Hierarchal structure with root servers at the top

Answer 39

Public Key Infrastructure (PKI)

Question 40

What is the structure of a PKI?

Answer 40

Certificate Authority (CA) – Intermediate Certificate Authority – users requesting certificates

Question 41

Distributes certificates to intermediate certificate authorities

Answer 41

Root Certificate Systems

Question 42

A group of public-key cryptography standards devised and published by RSA Security LLC.

Answer 42

PKCS (Public Key Cryptography Standards)

Question 43

Standard defining the format of public key certificates

Answer 43

X.509

Question 44

A way to store certificates in individual files

Answer 44

PKCS-7

Question 45

Stores the certificates and the private keys as a package

Answer 45

PKCS-12

Question 46

A list of digital certificates that have been revoked by the issuing certificate authority (CA) before their scheduled expiration date and should no longer by trusted

Answer 46

Certification Revocation list (CRL)

Question 47

An internet protocol used for obtaining the revocation status of an X.509 digital certificate

Answer 47

Online certificate status protocol (OCSP)

Question 48

Uses a text file full of dictionary words to performing a password (hash) attack

Answer 48

dictionary attack

Question 49

A precomputed table for reversing cryptographic hash functions, usually for cracking passwords

Answer 49

rainbow table attack

Question 50

Used to make a possibly weak key, typically a password or passphrase, more secure against a brute-force attack by increasing the resources (time and possibly space) it takes to test each possible key

Answer 50

keystretching technique (PKBDF2)

Question 51

Which part of the cryptography method is publicly available information?

Answer 51

the algorithm

Question 52

What are the two different types of cryptographic methods used for encryption?

Answer 52

symmetric and asymmetric

Question 53

PGP has been used by what service?

Answer 53

mail encryption