Encryption and keys

Question 1

how many keys does private key encryption use?

Answer 1

1

Question 2

how many keys does public key encryption use?

Answer 2

2

Question 3

how many keys does Kerberos user authentication use?

Answer 3

3

Question 4

what port is HTTPS

Answer 4

440

Question 5

What do you need to get the “s” in HTTPS?

Answer 5

A Secure Socket Layer (SSL) certificate.

Question 6

How do you get an SSL certificate?

Answer 6

By asking the Certification Authority to hand you one, they then check your public key, and check your encryption and other facts about your website.

Question 7

An SSL certificate is useful for three points, what are they?

Answer 7

They:
show that your website’s encryption is good,
show that the website is genuine
Allow the S in HTTPS

Question 8

what are the basics of private key encryption?

Answer 8

There is 1 key, shared by the sender and the receiver, the sender uses that key to encrypt, then the receiver uses the same key to decrypt.

Question 9

Disadvantage of using private key encryption?

Answer 9

You need to be able to send the key over safely, which is hard using this method, and if the key is compromised, they can read both parties’ conversations.

Question 10

what are the 2 ciphers for private key encryption?

Answer 10

Block cypher (in chunks of 64,128,256 bits)
stream cypher (bit by bit)

Question 11

name some user authentication methods:

Answer 11

setting strong passwords
graphical passwords
biometrics
security tokens
2 step authentication (2 factor authentication)
knowledge based
certificate based

Question 12

basics of public key encryption?

Answer 12

2 keys, one known by everyone, one private to you.
encrypt with private and the recipient’s public.
they decrypt using their private and your public.

can verify it was from a legitimate source.
very hard to eavesdrop.

Question 13

What are the 3 steps of Kerberos?

Answer 13

3 keys,
Username is hashed by pass,
auth. server does the same and check to see if it matches, sends key to TGS and user, along with a TGT.

User sends the TGT along with key to the TGS, TGS verifies the key and grants user a token (that states how long they can access etc) and a key, a key is also sent to the file server.

User gives token and key to file server, file server authenticates the key and allows access according to the token’s details.

Question 14

difference between IPV4 and IPV6?

Answer 14

IPV4 contains 32 bits, and just binary, separated by “.” holding 4 billion devices.

IPV6 contains 128 bits, binary and hexadecimal and separated by a “:” holding 340 Undecillion combinations (340 trillion trillion trillion)