Krüptograafilised protokollid 2021/22 sügis

Homework 2: Studying TLS from RFC8446

TLS is a very commonly used protocol and clearly there are many lectures, discussions and study materials about it available online. However, it is very important to also be able to get all the necessary information from the source that defines the protocol.

Answer the following questions based on the RFC of TLS 1.3 https://tools.ietf.org/html/rfc8446. Reference the relevant sections of the RFC in your answer but use your own words. Please submit the answers as a pdf or plaintext file.

• What is a zero round-trip time mode? What are its drawbacks and advantages? When can it be used?
• What is "insufficient_security" alert, who returns it and under which circumstances?
• What are the phases of the handshake protocol?
• During which phases of the protocol can the client send early data and what is it? How are the security properties of early data compared to other data in TLS connection?

Deadline: October 21st, 2021, 23:59 EEST.

Delivery:: upload through the course website (see below)