This course covers the TextSecure protocol for end-to-end encrypted messaging, focusing on cryptographic challenges like forward secrecy, multi-party and multi-device cases, authentication, and more. It also explores future possibilities such as emerging use cases, authentication approaches, federation, and metadata hiding. The course teaches skills in public key encryption, signed prekeys, key agreement, Diffie-Hellman encryption and authentication, symmetric-key ratchet, multi-party communication, and end-to-end encryption. The teaching method involves a talk format. The intended audience for this course includes individuals interested in cryptography, secure messaging protocols, and privacy advocates.
Overview
Syllabus
Intro
Open Whisper Systems . Founded by Moxie Marlinspike • Goal of making private communications simple
Security goals and model
Overview
Stateful protocol • First message creates a session based on keys from a key directory
Public key encryption
Signed prekeys
Signed & one-time prekeys
Key agreement
Diffie-Hellman encryption
Diffie-Hellman authentication
Symmetric-key ratchet
DH ratchet
Axolotl ratchet
Alice's initial message
Bob's response
Alice's response
Multi-party (sender keys)
Multi-device
End-To-End encryption and
Authenticating public keys
Taught by
NorthSec
