Final

Question 1

Three Modes/Use Cases for VPN

Answer 1

host to host, host to LAN, LAN to LAN

Question 2

VLAN

Answer 2

virtual local area network, virtually isolated networks from each other in a LAN

Question 3

three kinds of ciphers in cryptogtaphy

Answer 3

symmetric, public-key, one-way hashes

Question 4

VPN: full tunnels vs. split tunnels

Answer 4

full tunnel encrypts all traffic, split tunnels only select traffic

Question 5

proxy

Answer 5

a gateway/sever between the internet and users that processes your traffic and gives response back to you

Question 6

what does cryptography do/help with?

Answer 6

data protection, authentication, digital signature, data integrity

Question 7

public-key ciphers

Answer 7

two keys (public and private) undo whatever the other key did and vice versa (reversible)

Question 8

symmetric-key cipher

Answer 8

secret codeword/key both locks and unlocks data which is being protected (reversible)

Question 9

one-way hash / message digest

Answer 9

mapping functions from large set to a smaller set, collisions inevitable, but not predictable, it is irreversible…ex: SHA256, MD5(not used), SHA1(not used)

Question 10

block cipher vs stream cipher

Answer 10

block cipher from plain text to fixed size, stream encrypts one bit at a time (variable length)

Question 11

DMZ

Answer 11

Demilitarized Zone, is like a buffer zone between a private/internal network and the outside world, typically the internet. It’s designed to provide an extra layer of security for sensitive systems within a network.

Question 12

ways to break crypto

Answer 12

brute force, implementation mistakes, knowing some of the message, denial of service, social engineering( rubber-hose cryptography)

Question 13

cryptography authentication

Answer 13

can use certificates

Question 14

midterm: 3 ways to authenticate

Answer 14

something you know(passwords, personal IDs) , are(fingerprint, iris), have(phone, email)

Question 15

how do cryptosystems work to do message encryption

Answer 15

they take a low entropy text and turn it into a high entropy ciphertext which is mathematically indistinguishable from random data, in public keys, encrypt message using recivers public key, and decrypt with recievers private key

Question 16

digital signature

Answer 16

verifies authenticity (that the sender actually sent it), encrypt with private key, and decrypt with public key

Question 17

trusted computing

Answer 17

belief computers will operate in a predictable manner with authenticated and protected data