MaTRU‐KE: A key exchange protocol based on MaTRU cryptosystem

We propose a quantum ‐resistant key exchange protocol based on hard problems of lattices using MaTRU cryptosystem as an underlying scheme. A key exchange protocol based on NTRU cryptosystem given by Lie et al is not secure against man‐in‐the‐middle (MITM) attack. To remove this failure and provide a secure protocol, our protocol uses a trusted third party (TTP). Additionally, our protocol is better than NTRU‐KE on efficiency and security point of view. In this paper, we propose key exchange protocol with TTP and without TTP, and describe the advantages and disadvantages of both schemes.     

Cryptanalysis of an identity‐based authenticated key exchange protocol

Authenticated key exchange protocols represent an important cryptographic mechanism that enables several parties to communicate securely over an open network. Elashry, Mu, and Susilo proposed an identity‐based authenticated key exchange (IBAKE) protocol where different parties establish secure communication by means of their public identities.The authors also introduced a new security notion for IBAKE protocols called resiliency, that is, if the secret shared key is compromised, the entities can generate another shared secret key without establishing a new session between them. They then claimed that their IBAKE protocol satisfies this security notion. We analyze the security of their protocol and prove that it has a major security flaw, which renders it insecure against an impersonation attack. We also disprove the resiliency property of their scheme by proposing an attack where an adversary can compute any shared secret key if just one secret bit is leaked.     

Cryptanalysis of a simple three‐party password‐based key exchange protocol

In order to secure communications between two clients with a trusted server's help in public network environments, a three‐party authenticated key exchange (3PAKE) protocol is used to provide the transaction confidentiality and the efficiency. In 2009, Huang proposed a simple three‐party password‐based authenticated key exchange (HS‐3PAKE) protocol without any server's public key. By analysis, Huang claimed that the proposed HS‐3PAKE protocol is not only secure against various attacks, but also more efficient than previously proposed 3PAKE protocols. However, this paper demonstrates that HS‐3PAKE protocol is vulnerable to undetectable online password guessing attacks and off‐line password guessing attacks by any other user. Copyright © 2010 John Wiley & Sons, Ltd.     

A simple three‐party password‐based key exchange protocol

In three‐party password‐based key exchange (3PAKE) protocol, a client is allowed to share a human‐memorable password with a trusted server such that two clients can agree on a secret session key for secure connectivity. Recently, many 3PAKE protocols have been developed. However, not all of them can simultaneously achieve security and efficiency. Without any server's public key, this article will propose a simple three‐party password‐based authenticated key exchange scheme. Compared with the existing schemes, the proposed scheme is not only more efficient, but also is secure. Copyright © 2009 John Wiley & Sons, Ltd.     

On ‘a simple three‐party password‐based key exchange protocol’

In 2009, Huang (Int. J. Commun. Syst., 22 , 857–862) proposed a simple and efficient three‐party password‐based key exchange protocol without server's public key. This work shows that the protocol could be vulnerable to an undetectable online password guessing attack. Furthermore, an improved protocol is proposed to avoid the attack. Copyright © 2011 John Wiley & Sons, Ltd.     

A pairing‐free certificateless authenticated key agreement protocol

Many certificateless two‐party authenticated key agreement schemes using bilinear pairings have been proposed. But the relative computation cost of the pairing is approximately twenty times higher than that of the scalar multiplication over elliptic curve group In order to improve the performance we propose a certificateless two‐party authenticated key agreement scheme without bilinear pairings in this paper. A security proof under random oracle model is also provided. Copyright © 2011 John Wiley & Sons, Ltd.     

An efficient chaos‐based 2‐party key agreement protocol with provable security

Key agreement protocol is an important cryptographic primitive, which allows 2 parties to establish a secure session in an open network environment. A various of key agreement protocols were proposed. Nowadays, there still exists some other security flaws waiting to be solved. Owing to reduce the computational and communication costs and improve the security, chaotic map has been studied in‐depth and treated as a good solution. Recently, Liu et al proposed a chaos‐based 2‐party key agreement protocol and demonstrated that it can defend denial‐of‐service attack and replay attack. We found, however, it cannot resist off‐line password‐guessing attack, and it also has some other security flaws. In this paper, we propose an improved chaos‐based 2‐party key agreement protocol. The results prove that the protocol can solve the threats of off‐line password‐guessing attack and other security flaws in the security proof section. What is more, performance analysis shows that the computational cost of the improved protocol is lower than Liu et al protocol.     

Verifiable three-party secure key exchange protocol based on eigenvalue

In order to solve the problem that the traditional key exchange protocol,which was not flexible enough and flawed in security,cannot provide the function of three-party key negotiation,firstly,a simple and flexible three-party key exchange scheme that can resist man-in-the-middle attacks was proposed with the help of secret matrix eigenvalues.However,the validity of key exchange cannot be verified by the scheme,and counterfeiting by middlemen can’t be prevented.Then based on it,the secret matrix was reconstructed,where the matrix order was a large even number,and all the eigenvalues appeared in pairs,similar to the diagonal matrix.Based on the special secret matrix,the verification part which can be used to verify the legitimacy of the communication party was introduced to the scheme,and the verifiable three-party key exchange protocol based on the eigenvalue was given.The protocol not only solved the problem of three-party key exchange,but also verified identity legitimacy.It is proved that it’s feasible to design a three-party key exchange protocol by the eigenvalue.The final protocol is both secure and efficient.     

An ECC‐based authenticated group key exchange protocol in IBE framework

With the rapid demand for various increasing applications, the internet users require a common secret key to communicate among a group. The traditional key exchange protocols involve a trusted key generation center for generation and distribution of the group key among the various group members. Therefore, the establishment of a trusted key generation center server and the generation (and distribution) of common session key require an extra overhead. To avoid this difficulty, a number of group key exchange protocols have been proposed in the literature. However, these protocols are vulnerable to many attacks and have a high computational and communication cost. In this paper, we present an elliptic curve cryptography–based authenticated group key exchange (ECC‐AGKE) protocol, which provides better security and has lower computational cost compared to related proposed schemes. Further, a complexity reduction method is deployed to reduce the overall complexity of the proposed elliptic curve cryptography–based authenticated group key exchange protocol. The security of proposed work is ensured by the properties of elliptic curves. A security adversarial model is given and an extensive formal security analysis against our claim is done in the random oracle model. We also made a comparison of our proposed protocol with similar works and found that ours have better complexity, security and efficiency over others.     

A secure and efficient password‐authenticated group key exchange protocol for mobile ad hoc networks

Password‐authenticated group key exchange protocols enable communication parties to establish a common secret key (a session key) by only using short secret passwords. Such protocols have been receiving significant attention. This paper shows some security weaknesses in some recently proposed password‐authenticated group key exchange protocols. Furthermore, a secure and efficient password‐authenticated group key exchange protocol in mobile ad hoc networks is proposed. It only requires constant round to generate a group session key under the dynamic scenario. In other words, the overhead of key generation is independent of the size of a total group. Further, the security properties of our protocol are formally validated by a model checking tool called AVISPA. Security and performance analyses show that, compared with other related group key exchange schemes, the proposed protocol is also efficient for real‐world applications in enhancing the security over wireless communications. Copyright © 2011 John Wiley & Sons, Ltd.     

A novel and efficient lattice‐based authenticated key exchange protocol in C‐K model

Key exchange protocols play an important role in securing the network communication over an insecure channel. In literature, a large number of key exchange schemes exist. The security of most of them is based on the Diffie‐Hellman (DH) problems over a group. But these types of DH problems are solvable in the presence of quantum computers. Thus, we require a non‐DH type key exchange scheme that resists to the quantum computers and new modern technologies. In this paper, 2 novel lattice‐based authenticated key exchange (LB‐AKE) protocols, (1) using a signature‐based authenticator and (2) using a signcryption‐based authenticator, are devised in Canetti‐Krawczyk proof model. The security of proposed protocols depends on the hardness of small integer solutions on the lattice. An extensive proof of security to our claim is given. The proposed AKEs characterize faster computation speed and resistance to the modern complex computers.     

Strongly secure ID‐based authenticated key agreement protocol for mobile multi‐server environments

To provide mutual authentication and communication confidentiality between mobile clients and servers, numerous identity‐based authenticated key agreement (ID‐AKA) protocols were proposed to authenticate each other while constructing a common session key. In most of the existing ID‐AKA protocols, ephemeral secrets (random values) are involved in the computations of the common session key between mobile client and server. Thus, these ID‐AKA protocols might become vulnerable because of the ephemeral‐secret‐leakage (ESL) attacks in the sense that if the involved ephemeral secrets are compromised, an adversary could compute session keys and reveal the private keys of participants in an AKA protocol. Very recently, 2 ID‐AKA protocols were proposed to withstand the ESL attacks. One of them is suitable for single server environment and requires no pairing operations on the mobile client side. The other one fits multi‐server environments, but requires 2 expensive pairing operations. In this article, we present a strongly secure ID‐AKA protocol resisting ESL attacks under mobile multi‐server environments. By performance analysis and comparisons, we demonstrate that our protocol requires the lowest communication overhead, does not require any pairing operations, and is well suitable for mobile devices with limited computing capability. For security analysis, our protocol is provably secure under the computational Diffie‐Hellman assumption in the random oracle model.     

Efficient three‐party password‐based key exchange scheme

In three‐party password‐based key exchange protocol, a client is allowed to share a human‐memorable password with a trusted server such that two clients can negotiate a session key to communicate with each other secretly. Recently, many three‐party password‐based key exchange protocols have been developed. However, these proposed schemes cannot simultaneously achieve security and efficiency. Based on elliptic curve cryptography (ECC), this paper will propose a new simple three‐party password‐based authenticated key exchange scheme. The proposed method not only reduces computation cost for remote users and a trusted server but also is more efficient than previously proposed schemes. It is better suited for resource constrained devices, such as smart cards or mobile units. Copyright © 2010 John Wiley & Sons, Ltd.     

Secret key rates of free‐space optical continuous‐variable quantum key distribution

In this letter, we derive the maximal achievable secret key rates for continuous‐variable quantum key distribution (CVQKD) over free‐space optical (FSO) quantum channels. We provide a channel decomposition for FSO‐CVQKD quantum channels and study the SNR (signal‐to‐noise ratio) characteristics. The analytical derivations focus particularly on the low‐SNR scenarios. The results are convenient for wireless quantum key distribution and for the quantum Internet.     

Cryptanalysis and improvement of a three‐party password‐based authenticated key exchange protocol with user anonymity using extended chaotic maps

Three‐party password‐authenticated key exchange (3PAKE) protocols allow two clients to agree on a secret session key through a server via a public channel. 3PAKE protocols have been designed using different arithmetic aspects including chaotic maps. Recently, Lee et al. proposed a 3PAKE protocol using Chebyshev chaotic maps and claimed that their protocol has low computation and communication cost and can also resist against numerous attacks. However, this paper shows that in spite of the computation and communication efficiency of the Lee et al. protocol, it is not secure against the modification attack. To conquer this security weakness, we propose a simple countermeasure, which maintains the computation and communication efficiency of the Lee et al. protocol. Copyright © 2014 John Wiley & Sons, Ltd.     

Cryptanalysis and enhancements of efficient three‐party password‐based key exchange scheme

In this paper, we first showed that Lou and Huang's three‐party password‐based key exchange protocol is still vulnerable to offline dictionary attacks. Thereafter, we proposed an enhanced protocol that can defeat the attack described and yet is efficient. Finally, we provided the rigorous proof of the security for it. Copyright © 2011 John Wiley & Sons, Ltd.     

Securing Mobile Ad Hoc Networks Using Enhanced Identity‐Based Cryptography

Recent developments in identity‐based cryptography (IBC) have provided new solutions to problems related to the security of mobile ad hoc networks (MANETs). Although many proposals to solve problems related to the security of MANETs are suggested by the research community, there is no one solution that fits all. The interdependency cycle between secure routing and security services makes the use of IBC in MANETs very challenging. In this paper, two novel methods are proposed to eliminate the need for this cycle. One of these methods utilizes a key pool to secure routes for the distribution of cryptographic materials, while the other adopts a pairing‐based key agreement method. Furthermore, our proposed methods utilize threshold cryptography for shared secret and private key generation to eliminate the “single point of failure” and distribute cryptographic services among network nodes. These characteristics guarantee high levels of availability and scalability for the proposed methods. To illustrate the effectiveness and capabilities of the proposed methods, they are simulated and compared against the performance of existing methods.     

A scalable and efficient key escrow model for lawful interception of IDBC‐based secure communication

Key escrowing is one of the core technologies for the lawful interception (LI) of secure communications in the wired and wireless networks. Although many previous studies on the key escrowing have been done before, they are insufficient to be deployed in practical networks due to conflicts with the LI requirements. Moreover, there is lack of consideration on the LI of ID‐based cryptosystem (IDBC)‐based secure communication because the interest of the LI was moved to the industries and IDBC has the inherent key escrowing property. However, the inherent property of IDBC cannot prevent ‘illegal’ eavesdropping of all the communications in the networks from the law enforcement agency with the ‘legally’ obtained key. Thus, we propose a new key escrow model that satisfies the requirements of LI and overcomes the potential threats of IDBC. Our contributions enable the scalable and efficient key escrowing for the LI of secure one‐way and two‐pass communication in the mobile networks. Copyright © 2010 John Wiley & Sons, Ltd.     

An enhanced anonymous identity‐based key agreement protocol for smart grid advanced metering infrastructure

Sprouting populace mass within the urban areas furnishes critical challenges of providing uninterruptible community services to fulfill the primitive needs of inhabitants in smart cities. Smart cities facilitate and uplift the living standards of inhabitants through various smart systems or infrastructures, and smart grid is one of them. Secure transmission is a key requirement in the advanced metering infrastructure (AMI) of most smart grids, and key establishment cryptographic protocols can be used to achieve such a requirement. Designing efficient and secure key establishment protocols for AMI remains challenging. For example, in this paper, we reveal several weaknesses in the identity‐based key establishment protocol of Mohammadali et al (published in IEEE Trans Smart Grid, 2017), which is based on elliptic curves. We then improve their protocol and prove its security in the random oracle model. We also demonstrate that the improved protocol achieves both anonymity and untraceability, before presenting a comparative summary of the security and computational overheads of the proposed protocol and several other existing protocols.