Week 6

Question 1

What is TLS protocol?

Answer 1

Transport Layer Security protocol provides encrypted socket communication and authentication, based on public keys.

Question 2

What is a X.509 standard for certificates?

Answer 2

Contain a subject, their public key, issuer name etc.

Issuer signs the hash of this data.

To check - hash all data and check issuers public key.

Question 3

Where is TLS found in the internet protocol stack?

Answer 3

Between application and transport layers.

Question 4

What are some configuration weaknesses in TLS?

Answer 4

Cipher Downgrading - Cipher suite messages are not authenticated.

Self-Signed Certificates - Easy to MITM.

Question 5

How does TLS 1.3 improve TLS?

Answer 5

Removes obsolete cryptographic protocols.

Simplified handshake - efficiency gain.

Forward secrecy mandatory.

Intercepting TLS connections now only possible as active attacker performing MITM attack.

Question 6

How do VPNs work?

Answer 6

Virtual Private Networks allow you to securely connect to another network.

Question 7

How does Onion Routing work?

Answer 7

Routes traffic through a number (entry, middle and exit node) of proxies.

Each proxy only learns the IP of the proxy before and after.

Public key of each proxy is known.

Question 8

How is TLS secure?

Answer 8

All previous messages are hashed and encrypted with Kcs for integrity.

Used to verify communication on both ends is the same.