Flashcards in Cryptography Deck (258)

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1

## What does CIA mean in relation to Cryptography?

### Confidentiality, Integrity and Authentication

2

## What is non-repudiation?

### An action that cannot be denied

3

## Non-repudiation can be used to provide what 3 things?

### Identification, Authentication and Accountability

4

## What is a mono-alphabetic substitution?

### A system that uses only a single alphabet to encrypt and decrypt a message

5

## What is a practitioner of cryptography known as?

### Cryptographer

6

## What term is used to describe the science of deciphering cipher text without the cryptographic key?

### Cryptanalysis

7

## What is Cryptology?

### The science of cryptography and cryptanalysis

8

## What is a practitioner of Cryptology called?

### Cryptologist

9

## What is a plaintext message?

### A message in its original readable format

10

## What is a ciphertext message?

### A plaintext message that's been encrypted

11

## What other term can be used to describe decryption?

### Deciphering

12

## What are two methods of encrypting traffic on a network?

###
End-to-End encryption

Link encryption

13

## What type of encryption is used where a packets are encrypted at the original source and then decrypted once they reach the final destination?

### End-to-End encryption

14

## What are the two advantages of end-to-end encryption?

###
Speed

Overall security

15

## What is the downside to end-to-end encryption?

### Only data in encrypted, not routing information

16

## What is Link encryption?

### requires that each node (ie router) has separate key pairs for its upstream and downstream neighbours. Packets are encrypted and decrypted at each node along the network path

17

## What is the advantage of link encryption?

### Entire packet including routing information is encrypted

18

## What are the two disadvantages of link encryption?

###
- Latency

- Inherent vulnerability: If a node is compromised or a packets decrypted contents are cached on the router then the data can be compromised

19

## What is the hardware or software implementation that transfers plaintext into ciphertext known as?

### A cryptosystem

20

## What 3 properties must an effective cryptosystem have?

###
- efficient method of encrypting and decrypting keys on the system

- cryptosystem is easy to use

- strength of the cryptosystem depends on the secrecy of the keys

21

## What is a keyspace in relation to a cryptosystem?

### A range of all possible values for a key within a cryptosystem

22

## What is a keyspace in relation to a cryptosystem?

### A range of all possible values for a key within a cryptosystem

23

## What is a restricted algorithm?

### refers to an algorithm that must be kept secret in order to provide security.

24

## What is the disadvantage of a restricted algorithm?

### relies on secrecy of the keys rather than complexity of the algorithm used

25

## What are the two basic elements of a cryptosystem?

###
- Cryptographic algorithm

- Cryptovariable

26

## What is another term for a cryptographic algorithm?

### Cipher

27

## What is another term for a cryptovariable?

### Key

28

## What is key clustering?

### Clustering occurs when identical ciphertetx messages are generated form a plaintext message by using the same encryption algorithm but different encryption keys

29

## What is a weakness of key clustering?

### reduces the number of key combinations that must be attempted in a brute force attack due to a weakness in the cryptographic algorithm

30