# MTI/A0: modular arithmetic or elliptic curves?

In the Handbook of Applied Cryptography (Menezes, A. J.; van Oorschot, P. C. & Vanstone, S. A.) Protocol MTI/A0 key agreement (algorithm 12.53) described as $\mod p$-protocol. The survey Overview of Key Agreement Protocols (Ratna Dutta and Rana Barua) describes MTI/A0 as elliptic curve-protocol.

Unfortunately I have no access to original MTI article. How MTI-protocols were described originally?

• I don't know how they were described originally, but this protocol is a derivative of Diffie-Hellman. This can be instantiated with any group, for example $\mathbb{Z}_p^*$ or the points on an elliptic curve. If you replace all $\mathbb{Z}_p^*$ elements in Algorithm 12.53 by generic group elements, all should still work. – CurveEnthusiast Dec 15 '17 at 7:53
• @CurveEnthusiast Yes, I understand that this works in arbitrary group. My question is only about original MTI approach. – Alexey Ustinov Dec 15 '17 at 11:13
• I also can't access this (easily), sorry. Given that the article is from '86, when ecc was still in kindergarten, I would expect they give it the mod $p$ treatment. – CurveEnthusiast Dec 15 '17 at 11:24