1. A One Round Protocol for Tripartite Diffie Hellman By Dane Vanden Berg

2. ● Antoine Joux ● New form of an old Cryptographic Method ● Based off of ECDHE - Elliptic Curve Diffie Hellman Ephemeral Paper Abstract

3. ● Cryptographical uses in day to day ● Brief introduction on Diffie-Hellman Protocol ● Elliptic Curve Cryptography ● One Round Protocol For Tripartite Diffie-Hellman Full Ground

4. ● Email ● Secure Websites ● Online Signatures ● Purchases Cryptography and You

5. ● Discovered in 1976 ● the Diffie–Hellman protocol is one of the most famous cryptographic primitives. ● Intended for a shared secrecy of one key ● Intended for perfect forward secrecy ● ( a.k.a Trapdoor Function? ) What is Diffie Hellman

6. Backround Diffie Hellman Merkle

7. Diffie Hellman Merkle Example BobEveAlice b = 10g=5a = 8 p=23 B=5 10 mod 23A=5 8 mod 23 B=9 A=16 s=16 10 mod 23s=9 8 mod 23 s= 13s=13 B=9 A=16

8. Another approach to public key cryptography ECC - Elliptic curve cryptography

9. p: field parameters (modulo p) a,b: points on the curve G: Generator - cyclic group n: ord(G) - number of pts in G h: cofactor - should equal 1 Domain Parameters

10. Example

16. ● Shorter Encryption Key ● Fewer Resources ● Compare how much energy it takes to break a crypto algorithm and compare it to how much water you can boil. Why Elliptic Curves

17. Tripartite Diffie Hellman

18. ● Involves 3 participants ● Single pass of communications ● 1 can broadcast some data to other 2 Description

19. ● Allows for 3 people instead of 2 ● Only one round of communication ● Broadcasting doesn’t require all parties to be “alive” at once ● Trusted Third Party Pros

20. Example of Trusted Third Party

21. ● Open to middle man attacks ● If keys aren’t certified people aren’t sure who is who. Flaws

22. https://blog.cloudflare.com/a-relatively- easy-to-understand-primer-on-elliptic- curve-cryptography/ Joux, Antoine. “A One Round Protocol for Tripartite Diffie-Hellman.” Journal of Cryptology 17.4(2004):n. pag. Web. https://www.youtube.com/watch?v=F3zzNa42-tQ https://tools.ietf.org/html/draft-urien-tls-dh-tripartite-00 https://eprint.iacr.org/2004/079.pdf Work Cited