Question 1

_____offers a mechanism to accomplish four security goals: confidentiality, integrity, authentication, and nonrepudiation.

Accepted Answer

Cryptography

Question 2

True or false. A strong hash function is designed so that a message cannot be forged that will result in the same hash as a legitimate message.

Accepted Answer

true

Question 3

. The act of scrambling plaintext into cipertext is know as____.

Accepted Answer

encryption

Question 4

An algorithm used for cryptographic purposes is known as _____.

Accepted Answer

Public key

Question 5

True or false: Encryption ciphers fall into two general categories: symmetric[private] key and asymmetric[public] key.

Accepted Answer

true

Question 6

An encryption cipher that uses the same key to encrypt and decrypt is called a ____ key.

Accepted Answer

Symmetric(private)

Question 7

____ corroborates the indentity of an entity, whether the sender, the sender\'s computer, some device, or some information.

Accepted Answer

authentication

Question 8

Which of the following is one of the four basic forms of cryptographic attack?

Accepted Answer

All of the following:   Ciphertext-only attack;   known-plaintext attack;   chosen-plaintext attack;   chosen-ciphertext attack.

Question 9

True or false. The two basic types of ciphers are transposition and substitution.

Accepted Answer

True

Question 10

A _____ is used to detect forgeries.

Accepted Answer

Hash value

Question 11

DES, IDEA, RC4, and WEP are examples of ______.

Accepted Answer

Symmetric algorithms[or standards]

Question 12

A _____signature is a representation of a physical signature stored in a digital format.

Accepted Answer

Digitized

Question 13

Cryptography accomplishes four security goals:

Accepted Answer

Confidentiality, integrity, authentication, and nonrepudiation.

Question 14

______ is \"the act of writing secret characters\" according to Webster\'s dictionary.

Accepted Answer

Cryptography

Question 15

Cryptography deals with two types of information:

Accepted Answer

1. Unencrypted information.   2. Encrypted information.

Question 16

______is information in understandable form. Unencrypted information is plaintext, or cleartext.

Accepted Answer

Unencrypted information.

Question 17

____ is information in scramble form. _____ is ciphertext.

Accepted Answer

Encrypted information. Encrypted information.

Question 18

________ is the act of scrambling plaintext into ciphertext.

Accepted Answer

Encryption

Question 19

_____ is the act of unscrambling ciphertext into plaintext.

Accepted Answer

Decryption

Question 20

An _____ is a repeatable process that produces the same result when it receives the same input. In encryption uses a known mathematical process for performing its function.

Accepted Answer

algorithm

Question 21

A ___ is an algorithm to encrypt or decrypt information.

Accepted Answer

cipher

Question 22

These types of algorithms have no decryption algorithms, these are _______.

Accepted Answer

one-way algorithms.

Question 23

The output of a one-way algorithm is a ____.

Accepted Answer

hash.

Question 24

Every cipher and any plaintext you want to encrypt needs a _____. There are multiple users utilizing the same cipher techniques; ie. DES, RSA, Blowfish, randomizing.

Accepted Answer

key

Question 25

True or false: When using a key, the encryption cipher uses the cryptographic key to vary its output so that two correspondents can protect their information from anyone else who has the same cipher.

Accepted Answer

True.

Question 26

When using a key, by changing the key, you change the output of the _____function, even if the plaintext remains the same.

Accepted Answer

cryptographic

Question 27

Encryption falls into two general categories:

Accepted Answer

1. Private[symmetric] key.  2. public[asymmetric] key

Question 28

Those that use the same key to encrypt and decrypt are_____ciphers.

Accepted Answer

private[symmetric] key

Question 29

Those that use different keys to encrypt and decrypt are _____ciphers.

Accepted Answer

public[asymmetric] key

Question 30

The number of possible keys to a cipher is a ____.

Accepted Answer

keyspace

Question 31

Without any knowledge of the key, an attacker with access to an encrypted message and the description cipher could try every possible key to decode the message. This is a _____attack.

Accepted Answer

Brute-force.

Question 32

Assuming the cipher has no mathematical weakness, a large ____ usually means more security.

Accepted Answer

keyspace

Question 33

The most scrutinized cipher in history is the ______, modern computing has searched its keyspace of 72 quadrillion keys without finding a single mathematical weakness.

Accepted Answer

Data Encryption Standard[DES]

Question 34

Cryptography is going to protect:

Accepted Answer

1. Confidentiality.  2. Integrity.  3. Authentication.  4. Nonrepudiation.

Question 35

_____ keeps information secret from all but authorized people.

Accepted Answer

Confidentiality

Question 36

______ ensures no one, even the sender, changes information after transmitting it.

Accepted Answer

Integrity

Question 37

Cryptography can enforce integrity with two techniques:

Accepted Answer

1. Hashes, or  2. Checksum

Question 38

A _____ is a one-way calculation of information that yields a result usually much smaller than the original message.

Accepted Answer

checksum

Question 39

_____ ensures integrity of the message.

Accepted Answer

checksum

Question 40

____ is difficult to duplicate, for example, the ____ of the phone number 1-800-555-1212 could be the sum of each digit, 30. If you change one digit, the ____ no longer matches the expected value. You would question the integrity.

Accepted Answer

checksum; checksum; checksum

Question 41

____ is a complex technique using a robust mathematical process that are hard to reverse-engineer.

Accepted Answer

hashes

Question 42

_____ confirms the identity of an entity through usernames and passwords.

Accepted Answer

Authentication.

Question 43

To be able to authenticate in a _______ cryptography world, parties must first securely distribute keys among themselves. Key word \"shared\"

Accepted Answer

symmetric key

Question 44

During authentication, they could use ______ cryptography to distribute the symmetric keys. Then they would use the symmetric keys for subsequent correspondence.

Accepted Answer

asymmetric key

Question 45

______ cryptography offers a simpler means of authentication.

Accepted Answer

asymmetric key.

Question 46

Along with confidentiality, _____ cryptography is the cornerstone of Internet commerce.

Accepted Answer

Asymmetric key

Question 47

______ enables you to prevent a party from denying a previous statement or action.

Accepted Answer

non-repudiation

Question 48

Asymmetric key exchange offers stronger ____.

Accepted Answer

non-repudiation.

Question 49

A key just for the sender, creates unique timestamp, this is _____.

Accepted Answer

nonrepudiation.

Question 50

Cryptoanalysis mechanisms, you can break a cipher in two ways:

Accepted Answer

1. analyzing the ciphertext to find the plaintext.  2. Analyze the ciphertext and its associated plaintext to find the key.

Question 51

There are four basic forms of a cryptographic attack:

Accepted Answer

1. Ciphertext-only attack[COA].  2. Known Plain Text Attack [KPA].  3. Chosen Plain Text Attack.  4. Chosen ciphertext attack.

Question 52

In a _______, the cryptanalyst, has access only to a segment of encrypted data, and has no choice as to what that data may be.

Accepted Answer

ciphertext-only attack[COA]

Question 53

In a _______ , the cryptanalyst possesses certain pieces of information before and after encryption.

Accepted Answer

known plaintext attack[KPA]

Question 54

_______ uses ciphertext and the plaintext and then analyze what the key is.[Before and after encryption data is available]

Accepted Answer

Known plaintext attack[KPA]

Question 55

*In a ______, the cryptoanalyst can encrypt any information and observe the output.

Accepted Answer

Chosen plaintext attack

Question 56

** ____ is the best possible analysis.

Accepted Answer

chosen plaintext attack

Question 57

A _____ is a special case, it is particularly relevant to the asymmetric systems and hash functions.

Accepted Answer

chosen ciphertext attack

Question 58

Cryptanalysis has the following objectives:

Accepted Answer

1. Derive the plaintext of a target message.  2. Determine the key used to encrypt a target message.  3. Derive the algorithm used by a particular cipher.  4. Solve the general mathematical problem underlying the cryptography.

Question 59

In modern systems, the difficulty of breaking a cipher depends on the _____.

Accepted Answer

complexity of keys

Question 60

Ciphers come in two basic forms:

Accepted Answer

1. Transposition ciphers.  2. Substitution ciphers.

Question 61

A ______ rearranges characters or bits of data.

Accepted Answer

transposition cipher

Question 62

A _______ replaces bits, characters, or blocks of information with other bits, characters, or blocks.

Accepted Answer

substitution cipher.

Question 63

\"ATTACK AT DAWN\' example on pg 313 is an example of a _____.

Accepted Answer

Transposition cipher.

Question 64

One of the simplest substitution ciphers is the _____.

Accepted Answer

Caesar Cipher.

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