Deck 8: Cryptography

Question 1

Julius Caesar was associated with an early version of the transposition cipher.

Answer 1

True

Question 2

Nonrepudiation means that customers or partners can be held accountable for transactions,such as online purchases,which they cannot later deny.

Answer 2

True

Question 3

PKI systems are based on public key cryptosystems and include digital certificates and certificate authorities.

Answer 3

True

Question 4

The most common hybrid system is based on the Diffie-Hellman key exchange,which is a method for exchanging private keys using public key encryption.

Question 5

When an asymmetric cryptographic process uses the sender's private key to encrypt a message,the sender's public key must be used to decrypt the message.

Question 6

In 1917,Gilbert S.Vernam,an AT&T employee,invented a polyalphabetic cipher machine that used a non-repeating random key.

Question 7

The permutation cipher simply rearranges the values within a block to create the ciphertext.

Question 8

Hashing functions require the use of keys.

Question 9

Common implementations of RA include systems that issue digital certificates to users and servers;directory enrollment;key issuing systems;tools for managing the key issuance;and verification and return of certificates.

Question 10

The 3DES implements a block cipher with a variable block length and a key length of 128,192,or 256 bits.

Question 11

In 1953,Giovan Batista Belaso introduced the idea of the passphrase (password)as a key for encryption.

Question 12

Popular cryptosystems use a hybrid combination of symmetric and asymmetric algorithms.

Question 13

You cannot combine the XOR operation with a block cipher operation.

Question 14

The asymmetric encryption systems use a single key to both encrypt and decrypt a message.

Question 15

Sequence encryption is a series of encryptions and decryptions between a number of systems,wherein each system in a network decrypts the message sent to it and then reencrypts it using different keys and sends it to the next neighbor,and this process continues until the message reaches the final destination.

Question 16

DES uses a 64-bit key.

Question 17

Two hundred and eighty five computers can crack a 56-bit key in one year;ten times as many would do it in a little over a month.

Question 18

One encryption method made popular by spy movies involves using the text in a book as the key to decrypt a message.

Question 19

To perform the Caesar cipher encryption operation,the pad values are added to numeric values that represent the plaintext that needs to be encrypted.

Question 20

The AES algorithm was the first public key encryption algorithm.

Question 21

As DES became known as being too weak for highly classified communications,Double DES was created to provide a level of security far beyond that of DES._________________________

Question 22

The application header protocol provides secrecy for the content of a network communication.

Question 23

SSL builds on the encoding format of the Multipurpose Internet Mail Extensions protocol and uses digital signatures based on public key cryptosystems to secure e-mail.

Question 24

Once the attacker has successfully broken an encryption,he or she may launch a replay attack,which is an attempt to resubmit a recording of the deciphered authentication to gain entry into a secure source.

Question 25

A(n)registration authority issues,manages,authenticates,signs,and revokes users' digital certificates,which typically contain the user name,public key,and other identifying information._________________________

Question 26

Hash algorithms are public functions that create a hash value by converting variable-length messages into a single fixed-length value._________________________

Question 27

Standard-HTTP (S-HTTP)is an extended version of the Hypertext Transfer Protocol that provides for the encryption of individual messages transmitted via the Internet between a client and server.

Question 28

Plaintext or cleartext is the original unencrypted message,or a message that has been successfully decrypted._________________________

Question 29

A(n)key is the programmatic steps used to convert an unencrypted message into an encrypted sequence of bits that represent the message._________________________

Question 30

To translate means to decrypt,decode,or convert,ciphertext into the equivalent plaintext._________________________

Question 31

The SHTTP security solution provides six services: authentication by digital signatures,message encryption,compression,e-mail compatibility,segmentation,and key management.

Question 32

Dictionary attacks are a collection of brute-force methods that attempt to deduce statistical relationships between the structure of the unknown key and the ciphertext generated by the cryptosystem.

Question 33

Attackers may conduct an encrypted-plaintext attack by sending potential victims a specific text that they are sure the victims will forward on to others.

Question 34

Encryption methodologies that require the same secret key to encipher and decipher the message are using what is called public key encryption._________________________

Question 35

Symmetric encryption uses two different but related keys,and either key can be used to encrypt or decrypt the message._________________________

Question 36

The encapsulating security payload protocol provides secrecy for the contents of network communications as well as system-to-system authentication and data integrity verification.

Question 37

AES implements a block cipher called the Rijndael Block Cipher._________________________

Question 38

Encryption is a process of hiding the true meaning of information.

Question 39

Encryption is the process of converting the ciphertext message back into plaintext so that it can be readily understood._________________________

Question 40

Secure Electronic Transactions was developed by MasterCard and VISA in 1997 to protect against electronic payment fraud.

Question 41

The number of horizontal and vertical pixels captured and recorded is known as the image's depth._________________________

Question 42

In transport mode the entire IP packet is encrypted and is then placed as the content portion of another IP packet._________________________

Question 43

Bit stream methods commonly use algorithm functions like the exclusive OR operation (____).

A)XOR
B)EOR
C)NOR
D)OR

Question 44

____ is the amount of effort (usually in hours)required to perform cryptanalysis to decode an encrypted message when the key or algorithm (or both)are unknown.

A)Code
B)Algorithm
C)Key
D)Work factor

Question 45

A(n)distinguished name uniquely identifies a certificate entity,to a user's public key._________________________

Question 46

____ is the process of converting an original message into a form that is unreadable to unauthorized individuals.

A)Encryption
B)Decryption
C)Cryptology
D)Cryptography

Question 47

PGP uses the freeware ZIP algorithm to compress the message after it has been digitally signed but before it is encrypted._________________________

Question 48

ESP in transport mode can be used to establish a virtual private network,assuring encryption and authentication between networks communicating via the Internet._________________________

Question 49

The most popular modern version of steganography involves hiding information within files that contain digital pictures or other images._________________________

Question 50

Privacy Enhanced Mail was proposed by the Internet Engineering Task Force and is a standard that uses 3DES symmetric key encryption and RSA for key exchanges and digital signatures._________________________

Question 51

Internet Protocol Security is designed to protect data integrity,user confidentiality,and authenticity at the IP packet level._________________________

Question 52

Secure HTTP provides the Internet communication services between client and host without consideration for encryption of the data that is transmitted between client and server._________________________

Question 53

A(n)response attack is an attempt to resubmit a recording of the deciphered authentication to gain entry into a secure source._________________________

Question 54

An attacker may obtain duplicate texts,one in ciphertext and one in plaintext,and thus reverse-engineer the encryption algorithm in a known-plaintext attack scheme._________________________

Question 55

Secure Multipurpose Internet Mail Extensions builds on the encoding format of the Multipurpose Internet Mail Extensions protocol and uses digital signatures based on public key cryptosystems to secure e-mail._________________________

Question 56

____ is the information used in conjunction with an algorithm to create the ciphertext from the plaintext or derive the plaintext from the ciphertext.

A)Password
B)Cipher
C)Key
D)Passphrase

Question 57

In a(n)word attack,the attacker encrypts every word in a dictionary using the same cryptosystem as used by the target._________________________

Question 58

A(n)man-in-the-middle attack attempts to intercept a public key or even to insert a known key structure in place of the requested public key._________________________

Question 59

____ is the entire range of values that can possibly be used to construct an individual key.

A)Code
B)Keyspace
C)Algorithm
D)Cryptogram

Question 60

Diffie-Hellman key exchange uses asymmetric encryption to exchange session keys._________________________

Question 61

The CA periodically distributes a(n)____ to all users that identifies all revoked certificates.

A)CRL
B)RA
C)MAC
D)AES

Question 62

____ is a federal information processing standard that specifies a cryptographic algorithm used within the U.S.government to protect information in federal agencies that are not a part of the national defense infrastructure.

A)DES
B)2DES
C)AES
D)3DES

Question 63

Digital signatures should be created using processes and products that are based on the ____.

A)DSS
B)NIST
C)SSL
D)HTTPS

Question 64

The ____ algorithm was the first public key encryption algorithm developed (in 1977)and published for commercial use.

A)DES
B)RSA
C)MAC
D)AES

Question 65

A method of encryption that requires the same secret key to encipher and decipher the message is known as ____ encryption.

A)asymmetric
B)symmetric
C)public
D)private

Question 66

An X.509 v3 certificate binds a ____,which uniquely identifies a certificate entity,to a user's public key.

A)message digest
B)fingerprint
C)distinguished name
D)digital signature

Question 67

DES uses a(n)____-bit block size.

A)32
B)64
C)128
D)256

Question 68

A ____ is a key-dependent,one-way hash function that allows only specific recipients (symmetric key holders)to access the message digest.

A)signature
B)MAC
C)fingerprint
D)digest

Question 69

In a ____ attack,the attacker eavesdrops during the victim's session and uses statistical analysis of patterns and inter-keystroke timings to discern sensitive session information.

A)replay
B)timing
C)correlation
D)dictionary

Question 70

SHA-1 produces a(n)____-bit message digest,which can then be used as an input to a digital signature algorithm.

A)48
B)56
C)160
D)256

Question 71

The ____ protocol provides system-to-system authentication and data integrity verification,but does not provide secrecy for the content of a network communication.

A)ESP
B)AH
C)HA
D)SEP

Question 72

____ attacks are a collection of brute-force methods that attempt to deduce statistical relationships between the structure of the unknown key and the ciphertext that is the output of the cryptosystem.

A)Timing
B)Dictionary
C)Correlation
D)Man-in-the-middle

Question 73

More advanced substitution ciphers use two or more alphabets,and are referred to as ____ substitutions.

A)multialphabetic
B)monoalphabetic
C)polyalphabetic
D)polynomic

Question 74

____ functions are mathematical algorithms that generate a message summary or digest to confirm the identity of a specific message and to confirm that there have not been any changes to the content.

A)Hash
B)Map
C)Key
D)Encryption

Question 75

The ____ is responsible for the fragmentation,compression,encryption,and attachment of an SSL header to the cleartext prior to transmission.

A)Standard HTTP
B)SFTP
C)S-HTTP
D)SSL Record Protocol

Question 76

____ is the protocol used to secure communications across any IP-based network such as LANs,WANs,and the Internet.

A)PEM
B)SSH
C)IPSec
D)SET

Question 77

____ are encrypted messages that can be mathematically proven to be authentic.

A)Digital signatures
B)MAC
C)Message certificates
D)Message digests

Question 78

____ is an integrated system of software,encryption methodologies,protocols,legal agreements,and third-party services that enables users to communicate securely.

A)MAC
B)PKI
C)DES
D)AES

Question 79

____ is a hybrid cryptosystem that combines some of the best available cryptographic algorithms and has become the open-source de facto standard for encryption and authentication of e-mail and file storage applications.

A)PGP
B)DES
C)AH
D)ESP

Question 80

____ was developed by Phil Zimmermann and uses the IDEA Cipher for message encoding.

A)PEM
B)PGP
C)S/MIME
D)SSL