Twin Diffie-Hellman Research Articles

Simple Three Party Key Exchange Protocols via Twin Diffie-Hellman Problem

In 2005, Abdalla and Pointcheval suggested a new variation of the computational DH assumption called chosen based computational Diffie Hellman (CCDH) and presented SPAKE-1 and SPAKE-2 simple password based authenticated key exchange protocols. Since then several three party password authenticated key agreement protocols have been proposed based on CCDH assumption but most of them broken. In this paper, we propose two password based simple three party key exchange protocols via twin Diffie-Hellman problem and show that the proposed protocols provide greater security and efficiency than the existing protocols. The protocols are also verified using Automated Validation of Internet Security Protocols and Applications (AVISPA) which is a push button tool for the automated validation of security protocols and the result shows that they do not have any security flaws.

Identification Schemes from Key Encapsulation Mechanisms

We propose a generic way for deriving an identification (ID) scheme secure against concurrent man-in-the-middle attacks from a key encapsulation mechanism (KEM) secure against chosen ciphertext attacks on one-wayness (oneway-CCA). Then we give a concrete one-way-CCA secure KEM based on the Computational Diffie-Hellman (CDH) assumption. In that construction, the Twin Diffie-Hellman technique of Cash, Kiltz and Shoup is essentially employed. We compare efficiency of the ID scheme derived from our KEM with previously known ID schemes and KEMs. It turns out that our KEM-based ID scheme reduces the computation by one exponentiation than the currently most efficient one derived from the Hanaoka-Kurosawa one-way-CCA secure KEM, whose security is based on the same (CDH) assumption.

Provably Secure Identity-based Authenticated Key Agreement Protocols in Multiple PKG Environment

Most available identity-based authenticated key agreement protocols require that both protocol participants are from the same PKG(Private Key Generator) environment.However,safe communication is requisite between protocol participants that are from different PKG environment in practice.In this paper,a new identity-based AKA(Authenticated Key Agreement) protocol is proposed in multiple PKG environment,which makes use of a new technique called twin Diffie-Hellman problem.Moreover,the security of the proposed protocol can be reduced to the standard CDH and BDH assumption in the eCK model,which makes use of the "trapdoor test" technology proposed by Cash et al in Eurocrypt 2008.

Universally composable secure TNC model and EAP-TNC protocol in IF-T

This paper analyzes trusted network connect (TNC) protocols within the universally composable (UC) framework. We propose the first TNC model in the UC framework by first designing the TNC ideal functionality ℱTNC, the EAP ideal functionality ℱEAP and the EAP-TNC ideal functionality ℱE-PA. Then, we construct a trusted network connect protocol named TK-TNC that UC-realizes ℱTNC in the (ℱEAP, ℱE-PA)-hybrid model. Subsequently, we perform a security analysis on protocol D-H PN given in the TCG specification and show that this protocol cannot securely realize the EAP-TNC ideal functionality and be resistant to an attack. Finally, we propose an alternative protocol using the twin Diffie-Hellman key-exchange technique, named protocol TD-H PN, which can securely realize the EAP-TNC ideal functionality in the (ℱREG, ℱCERT)-hybrid model.

New RSA-Based (Selectively) Convertible Undeniable Signature Schemes

In this paper, we design and analyze some new and practical (selectively) convertible undeniable signature (SCUS) schemes in both random oracle and standard model, which enjoy several merits over existing schemes in the literature. In particular, we design the first practical RSA-based SCUS schemes secure in the standard model. On the path, we also introduce two moduli RSA assumptions, including the strong twin RSA assumption, which is the RSA symmetry of the strong twin Diffie-Hellman assumption (Eurocrypt'08).