Lesson 15

Question 1

Symmetric-key Cryptography

Also known as:

Answer 1

secret key or symmetric key encryption.

Question 2

Modern symmetric ciphers are known as ________because they involve multiple rounds where each round is made up of simple ciphers

Answer 2

round ciphers

Question 3

_________ divide plaintext into blocks and use the same key for encryption and decryption.

Answer 3

Block ciphers

Question 4

Three modern symmetric key ciphers are

Answer 4

DES, 3DES, AES

Question 5

asymmetric key encryption

also known as

Answer 5

Public/private key encryption

Question 6

Diffie - Hellman is a ___________ used to encrypt and decrypt ___________ over a public channel between two parties that have no prior knowledge of each other and was one of the first public - key protocols.

Answer 6

public - key cryptosystem

symmetric keys

Question 7

The _________ algorithm generates persistent asymmetric keys that can be used for encryption, digital signatures, and so on.

Answer 7

RSA Signature

Question 8

cryptographic hash

AKA

Answer 8

To get authentication and non - repudiation, (and data integrity),

Question 9

Hash Algorithms

Answer 9

MD5, SHA-1 and 2

Question 10

IPsec Protocols

Answer 10

ESP and AH

Question 11

Five Steps of IPsec

Answer 11

Interesting traffic:
IKE Phase 1: negotiate an IKE security policy (Secure channel)
IKE Phase 2: negotiate an IPsec security policy (Secure data)
Data Transfer
Tunnel terminated

Question 12

An __ is simply the bundle of algorithms and parameters that is being used to encrypt and authenticate a particular flow in one direction. Therefore, in normal bi - directional traffic, the flows are secured by a pair of security associations.

Answer 12

Security Associations (SA)