How To Exchange Secrets By OT.

Vladimir Kolesnikov, Ranjit Kumaresan

Abhishek Parakh

Key-exchange protocols have been overlooked as a possible means for implementing oblivious transfer (OT). In this article, we present protocols for mutual exchange of secrets, 1-out-of-2 OT and coin-flipping similar to the Diffie-Hellman protocol using the idea of obliviously exchanging encryption keys. Since the Diffie-Hellman scheme is widely used, our protocol may provide a useful alternative to the conventional methods for implementation of oblivious transfer and a useful primitive in building larger cryptographic schemes.

Wen‐Ai Jackson, Keith M. Martin, Christine M. O’Keefe

이용주, 최영일, 이병선

A fair exchange protocol enable two parties to exchange secrets with fairness, so that neither can gain any information advantage by quitting prematurely or otherwise misbehaving. Therefore a fair exchange is the most important for electronic transactions between untrusted parties. To design new fair exchange, after describing basic concepts, definitions and existing protocols and designing a non-interactive OT protocol using ELGamal's public key system, I will design new protocol to support fair exchange. In my designed new protocol, untrusted parties exchange secrets obliviously and verify that their received secrets are true by using transformed Zero Knowledge Interactive Proof extended to duplex. At this time, concerned two parties can't decrypt the other's ciphertext. After all of the steps, two parties can do it. It is the most important to provide perfect fairness and anonymity to untrusted parties in this protocol.

Erica Klarreich