In this paper, we propose an efficient and practical authenticated key exchange (AKE) protocol from ideal lattices, which is well-designed and has some similarity to the HMQV protocol. Using the hardness of the graded discrete logarithm (GDL) problem and graded decisional Diffie-Hellman (GCDH) problem, the proposed protocol is provably secure in the extended Canetti-Krawczyk model.

Many authentication and key exchange protocols are built using an accepted set of standard concepts such as Diffie–Hellman key exchange, nonces to avoid replay, certificates from an accepted authority, and encrypted or signed messages. We propose a general framework for deriving security protocols from simple components, using composition, refinements, and transformations. As a case study, we e...

Password-based encrypted key exchange are protocols that are designed to provide pair of users communicating over an unreliable channel with a secure session key even when the secret key or password shared between two users is drawn from a small set of values. In this paper, we present two simple password-based encrypted key exchange protocols based on that of Bellovin and Merritt. While one pr...

We present an NP decision procedure for the formal analysis of protocols in presence of modular exponentiation with products allowed in exponents. The number of factors that may appear in products is unlimited. We illustrate that our model is powerful enough to uncover known attacks on the A-GDH.2 protocol suite.

In this paper we show that the password-based Diffie-Hellman key exchange protocols due to Byun and Lee suffer from dictionary attacks.

This note describes a Diffie-Hellman oracle, constructed using standard Trusted Platform Module (TPM) signature APIs. The oracle allows one to compute the exponentiation of an arbitrary group element to a specified TPM-protected private key. By employing the oracle, the security provided by a group of order p is reduced by log k bits, provided k oracle queries are made and p± 1 is divisible by ...

We examine several variants of the Diffie-Hellman and Discrete Log problems that are connected to the security of cryptographic protocols. We discuss the reductions that are known between them and the challenges in trying to assess the true level of difficulty of these problems, particularly if they are interactive or have complicated input.

We present a variant of the Diffie-Hellman scheme in which the number of bits exchanged is one third of what is used in the classical Diffie-Hellman scheme, while the offered security against attacks known today is the same. We also give applications for this variant and conjecture a extension of this variant further reducing the size of sent information.

This paper explains the design and implementation of a highsecurity elliptic-curve-Diffie-Hellman function achieving record-setting speeds: e.g., 832457 Pentium III cycles (with several side benefits: free key compression, free key validation, and state-of-the-art timing-attack protection), more than twice as fast as other authors’ results at the same conjectured security level (with or without...

We present the SIGMA family of key-exchange protocols and the “SIGn-and-MAc” approach to authenticated Diffie-Hellman underlying its design. The SIGMA protocols provide perfect forward secrecy via a Diffie-Hellman exchange authenticated with digital signatures, and are specifically designed to ensure sound cryptographic key exchange while providing a variety of features and trade-offs required ...