This course aims to teach learners about CONIKS, an end-user key verification service for integration in end-to-end encrypted communication systems. The course covers the challenges specific to key verification for end users, the obviation of the need for global third-party monitors, and the ability for users to monitor their own key bindings efficiently. The course also discusses how CONIKS enables users and providers to collectively audit providers for non-equivocation while preserving user privacy. The teaching method includes lectures on the current state of end-to-end encrypted communication, challenges in trust establishment, the CONIKS solution, and its main security properties. The intended audience for this course includes individuals interested in cybersecurity, encryption, and privacy in communication systems.
Overview
Syllabus
Intro
E2E Encrypted Communication Today
Unsolved: How do users establish trust?
Out-of-Band Trust Est. = Unintuitive
Trust Est. by the Provider - Better?
Malicious Provider can Equivocate
Pros/Cons of Existing Trust Establishment
Ideal Trust Establishment Properties
Existing Approach: Verifying Correctness
Our Approach: Verifying Consistency
Solution: CONIKS
CONIKS - Registering a Key
CONIKS-Learning a User's Key
Strawman Consistency Checks: Verify All Bindings
CONIKS: Efficient Checks thru "Summaries"
CONIKS - Main Security Properties
1. Expected Bindings incl. in STR - Auth Paths
1. Checking Inclusion - Verify Auth Path
2. Non-Equivocation - STR History
2. Non-Equivocation - Clients see same STRS
2. Checking Non-Equivocation - Cross-Verification
Privacy Challenges in CONIKS
Main Performance Questions
CONIKS' Performance is Practical!
Conclusion
Taught by
USENIX
