cryptographic concepts

Question 1

_____ is the main component of ECDHE that gives it perfect forward secrecy.

Answer 1

Ephemeral key

Question 2

_____ uses ephemeral keys for each session which provide perfect forward secrecy.

Answer 2

ECDHE (ECC with D-H ephemeral mode)

Elliptic Curve Diffie Hellman Ephemeral

Question 3

_____ is a framework in which encryption is used to protect an expanding collection of transactional data registered in a public ledger.

Answer 3

Blockchain

Question 4

_____ is a trapdoor function used to generate public/private key pairs.

Answer 4

Elliptic Curve Cryptography (ECC)

Question 5

_____ function on different physical principles as classical computing and could put the strength of current cryptographic ciphers at risk, but also has the promise of underpinning more secure cryptosystems.

Answer 5

Quantum computers

Question 6

_____ is creating a key using thousands of rounds of hashing. Adding a salt in the hashing process makes the hash or key much stronger.

Answer 6

Key stretching

Question 7

A _____ is where a function produces the same hash value for two different inputs.

Answer 7

collision

Question 8

_____ is a two-way encryption algorithm in which encryption and decryption are both performed by a single secret key.

Answer 8

Symmetric encryption

Question 9

___ is an asymmetric algorithm used to create digital signatures. It can be used to encrypt short messages.

Answer 9

RSA

Question 10

_____ is an asymmetric algorithm used by NIST that adopts ElGamal’s algorithm. It uses the private and public keys from Diffie-Hellman in a similar way to RSA key pairs.

Answer 10

Digital Signature Algorithm (DSA)

Question 11

_____ is a symmetric block cipher using 64-bit blocks and a 56-bit key.

Answer 11

Data Encryption Standard (DES)

Question 12

_____ is a symmetric block cipher with a block size of 128 bits and key sizes of 128, 192, or 256 bits

Answer 12

Advanced Encryption Standard (AES)

This is faster and more secure than 3DES

Question 13

___ is a stream cipher meaning each byte or bit of data in the plaintext is encrypted one at a time.

Answer 13

RC4

Question 14

____ uses 64-bit blocks and a 56-bit key, but the plaintext is encrypted three times using different subkeys.

Answer 14

3DES

Question 15

In a _____, the plaintext is divided into equal-size blocks (usually 64- or 128-bit). Each block is then subjected to complex transposition and substitution operations, based on the value of the key used.

Answer 15

block cipher

Question 16

_____ ensures that a compromise of long-term encryption keys will not compromise data encrypted by these keys in the past.

Answer 16

Perfect forward secrecy

Question 17

An _____ is the main component of ECDHE that makes it a perfect forward secrecy. There is a different secret key for each session during transport.

Answer 17

ephemeral key

Question 18

_____ is a mode operation that will process the encryption in blocks using the same key. This is the simplest mod, and operates faster than CBC.

Answer 18

Electronic Code Book (ECB)

Question 19

_____is a mode of operation utilizing an Initialization Vector (IV). The output of the first ciphertext block is combined with the next plaintext block, and repeats. This is processing intensive and must run serially, hindering performance.

Answer 19

Cipher Block Chaining (CBC)