Chapter 6: Encryption and Password Cracking
TRUE/FALSE
1. Transposition relies on length of password.
2. Block ciphers operate on blocks of data.
3. As might be expected,Triple DES is almost three times faster than DES.
4. DSS stands for the United States government’s Digital Signature Standard, which is based on the Digital
Signature Algorithm (DSA).
5. Whether or not encryption is used, the use of password protection is open to various kinds of attack.
MULTIPLE CHOICE
1. ____ is a change in the position or order of letters or words, as in an anagram.
a.
Exchange
c.
Transposition
b.
Substitution
d.
Diffusion
2. ____ is the replacement of a letter or group of letters with another letter or group of letters.
a.
Substitution
c.
Exchange
b.
Diffusion
d.
Transposition
3. ____ ciphers use a key stream to encrypt and decrypt a plaintext message.
a.
Block
c.
Packet
b.
Bit
d.
Stream
4. ____ is a method for secure key exchange over an insecure channel based on the nature of photons.
a.
Skipjack
c.
RC4
b.
Quantum cryptography
d.
IDEA
5. ____ attacks use all possible combination of letters, numbers, and special characters to determine the
target password.
a.
Brute-force
c.
Hybridization
b.
Dictionary
d.
LC5
COMPLETION
1. ____________________ uses an algorithm to encrypt a ciphertext document from a plaintext document,
and when the information is needed again, the algorithm is used to decrypt the ciphertext back into
plaintext.
2. Sometimes called secret key algorithms, ____________________ key algorithms use the same key to
encrypt and to decrypt the data.
3. Also called public key algorithms, ____________________ key algorithms use two keys for encrypting
and decrypting data.
4. The ____________________, also known as Rijndael, is a block cipher adopted as an encryption
standard by the U.S. government.
5. ____________________ is a secure hash algorithm developed in 1992 by Ron Rivest,one of the
inventors of RSA.
SHORT ANSWER
1. Briefly describe Enigma.
2. Describe some of the most common terms you need to know when dealing with cryptography.
3. Briefly describe 3DES.
4. What are the main properties of Diffie-Hellman?
5. What are the cracking modes supported by John the Ripper?
