MODULE 6: COMMUNICATION TECHNOLOGIES

Question 1

Encryption

Answer 1

Transforming info that can’t be read

Question 2

Decryption

Answer 2

Transforming it into its original form

Question 3

Cryptography

Answer 3

Math to encrypt and decrypt data

Question 4

Pig Pen Cipher

Answer 4

Uses dots & boxes

Question 5

Dancing Men Cipher

Answer 5

Stick men code

Question 6

Caesar’s Cipher

Answer 6

Letters shift by a certain number

Question 7

Vigenere Cipher

Answer 7

A = 0…Z = 25

Question 8

Symmetric Encryption

Answer 8

Encrypt to decrypt (same key)

Question 9

Asymmetric Encryption

Answer 9

Encrypt (public key) to Decrypt (private key)

Question 10

Encryption Formula

Answer 10

C = E(M) = M x Pb

Question 11

Decryption Formula

Answer 11

M = D(C) = C x Pv
Pv = D(1/Pb)

Question 12

Goals of Coding Theory

Answer 12

Error Detection & Corrections

Question 13

Source Coding

Answer 13

Changing message to suitable code

Question 14

Sourcing Encoder

Answer 14

Transforms output into a sequence of symbols

Question 15

Codeword

Answer 15

String of Binary digits representing a message

Question 16

Code

Answer 16

Collection of all codewords

Question 17

Parity

Answer 17

Even or Odd

Question 18

Even Parity

Answer 18

Number of 1’s is even

Question 19

Odd Parity

Answer 19

Number of 1’s is odd

Question 20

Hamming Code

Answer 20

X1 + X2 + X3 + X4 + X5 + X6 +7

Question 21

Hamming Distance

Answer 21

Just find the number of differences each code has

Question 22

Nearest Neighbor Decoding

Answer 22

D(y) = Cn

Question 23

How to get X5

Answer 23

X1 + X2 + X4

Question 24

How to get X6

Answer 24

X1 + X3 + X4

Question 25

How to get X7

Answer 25

X2 + X 3 + X4

Question 26

Minimum Distance

Answer 26

2e + 1

Question 27

Error Detection

Answer 27

2e

Question 28

Error Correction

Answer 28

E (if decimal, round down)