Hellman Protocol Research Articles

A Session Hijacking Attack Against a Device-Assisted Physical-Layer Key Agreement

Physical-layer key agreement is used to generate a shared key between devices on demand. Such schemes utilize the characteristics of the wireless channel to generate the shared key from the device-to-device channel. As all characteristics are time-dependent and location-dependent, it is hard for eavesdroppers to get the key. However, most research works in this area use passive attack models whereas active attacks that aim at manipulating the channel and key are also possible. Physical-layer key agreement with User Introduced Randomness (PHY-UIR) is a solution similar to the Diffie–Hellman protocol against such a kind of active attack. The users (devices) introduce their own randomness to help to prevent active attacks. In this paper, we analyze the possibility of launching a session hijacking attack on PHY-UIR to allow an attacker to control the shared key established. The session hijacking attack manipulates the key agreement through a man-in-the-middle interaction and forces legitimate devices to run the PHY-UIR protocol with the attacker. Our simulation and experiment results validate our attack and show the high performance of our attack on manipulating the generated key. We also propose PHY-UIR $ ^{+}$ where devices simultaneously exchange information about the established shared keys, which allows them to detect whether they have agreed to different keys with a third party.

Понятие шифрование данных. Протокол Диффи-Хеллмана

Понятие шифрование данных. Протокол Диффи-Хеллмана

Версия протокола Диффи - Хеллмана, использующая дополнительные скрытые множители

Версия протокола Диффи - Хеллмана, использующая дополнительные скрытые множители

The Montgomery ladder on binary elliptic curves

In this survey paper, we present a careful analysis of the Montgomery ladder procedure applied to the computation of the constant-time point multiplication operation on elliptic curves defined over binary extension fields. We give a general view of the main improvements and formula derivations that several researchers have contributed across the years, since the publication of Peter Lawrence Montgomery seminal work in 1987. We also report a fast software implementation of the Montgomery ladder applied on a Galbraith–Lin–Scott (GLS) binary elliptic curve that offers a security level close to 128 bits. Using our software, we can execute the ephemeral Diffie–Hellman protocol in just 95,702 clock cycles when implemented on an Intel Skylake machine running at 4 GHz.

Elementary Algorithms Analysis of Megrelishvili Protocol

This article presents an investigation of asymptotic time complexities of several algorithms related to Megrelishvili protocol. The analysis are carried out for the private keys computations and public exchange of values, public key constructions, as well as an elementary exhaustive search attack algorithm. We show that the complexities of these algorithms are higher than the complexities of elementary algorithms involved in the conventional Diffie - Hellman protocol (DHP) or its variant on elliptic curves (ECDHP). This condition also implies that Megrelishvili protocol is more secure than DHP and ECDHP against exhaustive search attack.

A nonlinear decomposition attack

AbstractThis paper introduces a new type of attack, termed a nonlinear decomposition attack, against two known group-based key agreement protocols, namely, protocol based on extensions of (semi)groups by endomorphisms introduced by Kahrobaei, Shpilrain et al., and the noncommutative Diffie–Hellman protocol introduced by Ko, Lee et al. This attack works efficiently in the case when finitely generated nilpotent (more generally, polycyclic) groups are used as platforms. This attack is based on a deterministic algorithm that finds the secret shared key from the public data in both the protocols under consideration. Furthermore, we show that in this case one can break the schemes without solving the algorithmic problems on which the assumptions are based. The efficacy of the attack depends on the platform group, so it requires a more thorough analysis in each particular case.

Distributed key agreement for group communications based on elliptic curves. An application to sensor networks.

Internet of Things is built on sensor networks, which are enabling a new variety of solutions for applications in several fields (defense, health, and industry). Wireless communications are key for taking full advantage of sensor networks but implies new challenges in the security and privacy of communications. Security in wireless sensor networks is a major challenge for extending its applications. Moreover, the restrictive processing capabilities of sensor nodes have made the encryption techniques devised for conventional networks not feasible. In such setting, symmetric‐key ciphers are preferred for key management in wireless sensor network; key distribution is therefore an issue solved by means of the protocols presented in this paper. Diffie–Hellman protocol (since its development) has been in the most important cryptographic primitive being the base for plenty of security protocols. In this paper, we proposed three key exchange protocols derived from the Diffie–Hellman method, applied to elliptic curves, named ECGDH‐1, ECGDH‐2, and ECGDH‐3. Each performs secure key distribution sharing a group key among different nodes optimizing different network parameters. The security of the methods is based upon the difficulty of solving the discrete logarithm problem on elliptic curves. Making its application feasible to restrictive environments. Copyright © 2015 John Wiley & Sons, Ltd.

Forsakes: A forward-secure authenticated key exchange protocol based on symmetric key-evolving schemes

This paper suggests a model and a definition for forward-secure authenticated key exchange (AKE) protocols, which can be satisfied without depending on the Diffie--Hellman assumption. The basic idea is to use key-evolving schemes (KES), where the long-term keys of the system get updated regularly and irreversibly. Protocols conforming to our model can be highly efficient, since they do not require the resource-intensive modular exponentiations of the Diffie--Hellman protocol. We also introduce a protocol, called FORSAKES, and prove rigorously that it is a forward-secure AKE protocol in our model. FORSAKES is a very efficient protocol, and can be implemented by merely using hash functions.

A new two-round dynamic authenticated contributory group key agreement protocol using elliptic curve Diffie–Hellman with privacy preserving public key infrastructure

In this paper a new two-round authenticated contributory group key agreement based on Elliptic Curve Diffie–Hellman protocol with Privacy Preserving Public Key Infrastructure (PP-PKI) is introduced and is extended to a dynamic authenticated contributory group key agreement with join and leave protocols for dynamic groups. The proposed protocol provides such security attributes as forward secrecy, backward secrecy, and defense against man in the middle (MITM) and Unknown key-share security attacks and also authentication along with privacy preserving attributes like anonymity, traceability and unlinkability. In the end, they are compared with other popular Diffie–Hellman and Elliptic Curve Diffie–Hellman based group key agreement protocols and the results are found to be satisfactory.

Explicit constructions of extremal graphs and new multivariate cryptosystems

New multivariate cryptosystems are introduced. Sequences f(n) of bijective polynomial transformations of bijective multivariate transformations of affine spaces Kn, n = 2, 3, ... , where K is a finite commutative ring with special properties, are used for the constructions of cryptosystems. On axiomatic level, the concept of a family of multivariate maps with invertible decomposition is proposed. Such decomposition is used as private key in a public key infrastructure. Requirements of polynomiality of degree and density allow to estimate the complexity of encryption procedure for a public user. The concepts of stable family and family of increasing order are motivated by studies of discrete logarithm problem in Cremona group. Statement on the existence of families of multivariate maps of polynomial degree and polynomial density with the invertible decomposition is formulated. We observe known explicit constructions of special families of multivariate maps. They correspond to explicit constructions of families of nonlinear algebraic graphs of increasing girth which appeared in Extremal Graph Theory. The families are generated by pseudorandom walks on graphs. This fact ensures the existence of invertible decomposition; a certain girth property guarantees the increase of order for the family of multivariate maps, good expansion properties of families of graphs lead to good mixing properties of graph based private key algorithms. We describe the general schemes of cryptographic applications of such families (public key infrastructure, symbolic Diffie—Hellman protocol, functional versions of El Gamal algorithm).

A Novel Elliptic Curve Cryptography Based Approach of Re-watermarking for Cheque Truncation System

Cheque Truncation System (CTS) is a technique of preventing tangible movement of cheque by substituting it with a digital image, with an aim for secure and faster clearance. For the first time re-watermarking is applied for authenticating transactions in CTS. Methodology for the proposed approach splits the host image (Ih) into two layers (L). In L1 cheque details are fused with two image color channels to form a composite message (Cm). Secure hash algorithm (SHA-512) is applied to Cm to generate a unique message digest (Md). Elliptic Curve Digital Signature Algorithm (ECDSA) is applied to Md to create a digital signature. The signature is embedded by exploiting Human Visual System (HVS) color channel sensitivity in equally parted mode. In L2, joint secret is established to form key using Elliptic Curve Diffie Hellman Protocol (ECDHP). Advanced Encryption Standard (AES) is applied to user details intricate in the transaction. Encrypted contents are then inserted in L2 by applying Discrete Cosine Transform (DCT). Experimental results state solution to integrity concerns by using ECDSA with SHA-512, reaction to security issues by AES and the response to key distribution problem by ECDHP. An effective semi-blind CTS is perceived with PSNR between 59-60 dB.

Pairing Inversion for Finding Discrete Logarithms

This paper proposes an inversion algorithm for pairings. This technique can be used for breaking the Diffie–Hellman protocol on elliptic curves and for solving the discrete logarithm problem on some curves that satisfy GOST P.34.10-2012.

Noncommutative analogue of Diffie-Hellman protocol in matrix ring over the residue ring

Abstract. Classical Diffie-Hellman protocol of the key establishment was the basis of the development of several key exchange protocols. But this protocol is not secure and it is not protected against the “man in the middle” attack. The purpose of this article is to offer a secure and practical noncommutative analogue of the Diffie–Hellman protocol that is reliably protected not only against “man in the middle” attack but also against the quantum computer attack

Secure SCADA communication by using a modified key management scheme

This paper presents and evaluates a new cryptographic key management scheme which increases the efficiency and security of the Supervisory Control And Data Acquisition (SCADA) communication. In the proposed key management scheme, two key update phases are used: session key update and master key update. In the session key update phase, session keys are generated in the master station. In the master key update phase, the Elliptic Curve Diffie–Hellman (ECDH) protocol is used. The Poisson process is also used to model the Security Index (SI) and Quality of Service (QoS). Our analysis shows that the proposed key management not only supports the required speed in the MODBUS implementation but also has several advantages compared to other key management schemes for secure communication in SCADA networks.

Preserving data integrity in mobile ad hoc networks with variant Diffie‐Hellman protocol

AbstractSince the early 1990s, engineers have proposed many mechanisms for providing confidential communications and data integrity in mobile ad hoc networks (MANET). The deficiency of fastened infrastructure makes mobile ad hoc networks more vulnerable to security threats than conventional wireless networks. MANET can be considered as a short‐lived collection of mobile nodes that communicate with each other in between. All involved nodes in the network system share the responsibility for routing, accessing, and communicating. The main challenges on the design of MANET include high power saving and low bandwidth. The public key infrastructure (PKI) is a well‐known mechanism used to provide data integrity and confidential communications in MANET recently. The computation loads of PKI, however, are heavy to each mobile node in the cluster. Without adopting PKI cryptosystems to en/decrypt messages, we propose a novel version based on a variant Diffie‐‐Hellman protocol. The novel method can preserve the forward and backward secrecy of group communications. Specifically, the new method outperforms related works in the computation overheads of involved nodes while communicating with other nodes. Copyright © 2008 John Wiley & Sons, Ltd.

Strong password-based authentication in TLS using the three-party group Diffie Hellman protocol

The internet has evolved into a very hostile ecosystem where 'phishing' attacks are common practice. This paper shows that the three-party group Diffie-Hellman key exchange can help protect against these attacks. We have developed password-based ciphersuites for the Transport Layer Security (TLS) protocol that are not only provably secure but also believed to be free from patent and licensing restrictions based on an analysis of relevant patents in the area.

A secure and scalable Group Key Exchange system

We present a Group Key Exchange protocol which extends in a natural way the Diffie–Hellman protocol. Our protocol is scalable: it has two rounds (for n > 2 parties) and the number of modular exponentiations per user is constant. It is secure against a passive adversary if the Diffie–Hellman problem is intractable.

Cryptanalysis of an Authentication Key Exchange Protocol

Abstract: An authenticated multiple-key agreement protocol uses a digital signature to sign the Diffie-Hellmanpublic keys which can generate multiple session key in a single round of message exchange and achieve mutualauthentication. Recently, Hwang et al . proposed an authentication key exchange protocol which takes lesscomputation time than Harn and Lin’s protocol. However, this study, shows that Hwang et al .’s protocol sivulnerable to forgery attacks. An attacker can fool one communication part into believing the forged short-termpublic keys and share session keys with him. Key words: Authentication, cryptanalysis, key agreement, multiple-key INTRODUCTION In 1998, based on the MQV protocol, Harn and LinIn 1976, the key agreement protocol was introduced without using one-way functions. Summarily, Harn andby Diffie and Hellman [1]. The two parties were able o Lin’st protocol contain the authentication for the establish a secret session key over an insecure channel, Diffie-Hellman protocol. The two communication entitiessuch that the confidential information was transmitted can establish multiple session keys in one round f osecurely. However, the Diffie and Hellman protocol could interaction and use simple key computations.not provide authentication of the two parties. In other Unfortunately, Yen and Joye pointed out that Harnwords, the two parties could not authenticate each other. and Lin’s protocol had a security flaw; it suffered fromTo solve this problem, there are two ways to integrate forgery attacks. If a valid short-term public key pair s iauthentication into a key agreement protocol. One given, an attacker can forge a new short-term public keyapproach uses a pre-shared password

A One Round Protocol for Tripartite Diffie–Hellman

In this paper we propose a three participants variation of the Diffie--Hellman protocol. This variation is based on the Weil and Tate pairings on elliptic curves, which were first used in cryptography as cryptanalytic tools for reducing the discrete logarithm problem on some elliptic curves to the discrete logarithm problem in a finite field.

The Diffie–Hellman Protocol

The 1976 seminal paper of Diffie and Hellman is a landmark in the history of cryptography. They introduced the fundamental concepts of a trapdoor one-way function, a public-key cryptosystem, and a digital signature scheme. Moreover, they presented a protocol, the so-called Diffie–Hellman protocol, allowing two parties who share no secret information initially, to generate a mutual secret key. This paper summarizes the present knowledge on the security of this protocol.