Chapter 8 Cryptography

Question 1

Cryptography

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Answer 1

The science of altering information so that it cannot be decoded without a key.

Question 2

Cipher

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Answer 2

a method used to encode characters to hide their value

Question 3

Substitution Ciphers

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Answer 3

a type of coding or ciphering system that changes one character or symbol into another

Question 4

Ceasar Cipher

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Answer 4

oldest known substitution ciphers known for shifting all letters a certain number

Question 5

Vigenere cipher

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Answer 5

uses keyword to look up the cipher text in a table

Question 6

Transposition cipher

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Answer 6

involves transposing or scrambling the letters in a certain manner

Question 7

Rail Fence Cipher

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Answer 7

the message letters out diagonally over a number or rows and then read off cipher row by row

Question 8

Enigma Machine

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Answer 8

essentially a typewriter that implemented a multi-alphabet substitution cipher

Question 9

Steganography

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Answer 9

the process of hiding a message in a medium such as a digital image, audio file, or other file. Doing this prevents analyst from detecting the real message.

Question 10

Symmetric algorithms

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Answer 10

requires both ends of an encrypted message to have the same key and processing algorithms

Question 11

Symmetric key

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Answer 11

referred to a secret key or a private key, that is disclosed to people who aren’t authorized to use the encryption system

Question 12

Block cipher

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Answer 12

The algorithm works on chunks of data- encrypting on eo and then moving to the next

Question 13

Stream cipher

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Answer 13

the data is encrypted one bit or byte at a time

Question 14

Data Encryption Standard

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Answer 14

used since the mid 70’s, it was primary standard used int he government and the industry until it was replaced by AES

Question 15

Triple-DES

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Answer 15

technology upgrade of DES, still used even tho AES is preferred choice for government aplications

Question 16

Advanced Encryption Standard

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Answer 16

has replaced DES as the current standard and uses the Rijnael algorithm

Question 17

AES256

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Answer 17

uses 256 bits instead of 128. This qualifies for US government classification as Top Secret

Question 18

Cast

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Answer 18

is an algorithm developed by Carlisle Adams and Stafford Tavares. still used in some products offered by MIcrosoft and IBM

Question 19

Ron’s Cast

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Answer 19

is an encryption family produced by RSA labs. uses keys size of up to 2048 considered to be a strong system

Question 20

Blowfish and Twofish

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Answer 20

an encryption system invented by a team led by Bruce Schneier that performs a 64-block cipher at very fast speeds. Twofish uses a 128 block

Question 21

International Data Encryption Algorithm

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Answer 21

IDEA was developed by a Swiss consortium. Its an algorithmt hat uses a 128 bit key

Question 22

One -time Pads

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Answer 22

are the only truly completely secure crptographic implementations. secure for two reasons. They use a key that is as long as a text message. That means there isnt a pattern in the key application for an attacker to use

Question 23

Key Exchange

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Answer 23

in band key exchange and out of key exchange. In band essentially means that the key is exchanged in the same communications