Security Analysis of a Multi-factor Authenticated Key Exchange Protocol

This chapter explains the elements of key exchange, specifically the steps in a key exchange protocol, the parties that are involved and the messages which may be sent. It details key exchange security models and protocols, considering first the simpler case of unauthenticated key exchange before turning to authenticated protocols. The chapter deals with key exchange protocols designed to be secure against a passive adversary. It examines that unauthenticated protocols may be used as building blocks for authenticated key exchange protocols. Key exchange protocols that allow parties to verify the identity of other participating parties are called authenticated key exchange protocols. Key exchange has a long history and a vast literature, yet remains a very active research area with significant practical impact. It is inevitable that as new computational assumptions emerge as the basis for cryptographic security, so will their use in key exchange be relevant.

The key exchange protocol is the most important cryptography mechanism to protect end-to-end communications by the secret session key encryption. This paper focuses on the four-party key exchange protocol in a environment in which two clients (or UEs) are registered under two distinct servers. We propose a Three-Way Key Exchange and Agreement Protocol, denoted by TW-KEAP. It makes two communication parties have a secret session key to protect their subsequent communications on an efficient way, and intends the servers to involve with the key exchange procedure to derive the session key for the lawful interception support. Security analyses show that it provides mutual authentication, replay attack protection and perfect forward secrecy. Furthermore, the TW-KEAP has not only the shortest total service time based on the experimental results but also the shortest queuing delay from the queuing model analyses, as compared with current alternatives.

In cryptography, the key exchange protocol is very important before starting secure communication. Both parties will use an asymmetric key algorithm to exchange their keys for encryption and decryption. One of the methods to securely exchange the keys is Diffie-Hellman Key Exchange (DHKE) protocol. DHKE allows both parties to exchange their keys over the insecure public channel safely. However, DHKE protocol does not authenticate the message, making it easily exposed to third-party interruptions like Man-in-the-Middle (MitM) attack. Therefore, Station to Station (STS) protocols was introduced after modifying the DHKE protocol and adding authentication elements. Thus, this paper proposes to provide the authentication of the STS protocol by using Lamport Digital Signature Scheme. Lamport Digital Signature Scheme, also known as Lamport one-time signature scheme, gives very strong security because it can be built from any cryptographically secure one-way function and usually uses a cryptographic hash function. The results from the study are STS protocol algorithms that provide a verification scheme using the Lamport Digital Signature Scheme. As a result, both parties will obtain a common key for encryption and decryption, in which both parties play a role by using their respective digital signature for verification within the STS of this protocol

Security issues play an important role in modern communication worlds. Via distrusted networks, exchanged messages need to be encrypted by a session key for security requirements. Session keys are preferred to be generated by communication parties, and how to authenticate the other communication party is an important problem needed to be solved. In three-party encrypted key exchange (3PEKE) protocols, a special type of indirect-authenticated protocols, a trusted third party is involved to have two communication parties be able to authenticate each other and negotiate one session key. In 2008, Yoon and Yoo proposed a three-party encrypted key exchange protocol and claimed their protocol provides a more secure way for exchanging messages. Unfortunately, we find that their protocol suffers from undetectable one-line password guessing attacks. In this manuscript, we first review the important related works and show how to mount attacks on Yoon and Yoo’s 3PEKE protocol

키 교환 프로토콜은 공개 네트워크상에서 안전한 통신 채널을 구축하는데 필수적인 요소이다. 특히, 패스워드 기반 키 교환 프로토콜에서는 패스워드를 이용하여 사용자 인증이 이루어지며 이를 바탕으로 안전하게 키 교환이 이루어지도록 설계되어야 한다. 그러나 패스워드는 인간이 쉽게 기억할 수 있는 반면에 엔트로피가 낮고 따라서 사전공격에 쉽게 노출될 수 있다. 최근, Zhao와 Gu가 서버의 도움을 필요로 하는 새로운 패스워드 기반 키 교환 프로토콜을 제안하였다. Zhao와 Gu가 제안한 프로토콜은 일회성 비밀키의 노출 상황을 고려하는 공격자 모델에서도 안전성이 증명가능하다고 주장하였다. 본 논문에서는 Zhao와 Gu의 프로토콜에 대한 재전송 공격을 통하여 이 프로토콜이 저자들의 주장과 달리 일회성 비밀키의 노출 시에 안전하지 않다는 것을 보일 것이다. 본 연구 결과는 Zhao와 Gu가 제시한 안전성 증명이 성립하지 않음을 의미한다.

Abstract—Modular design is a common approach for dealing with complex tasks in modern cryptology. The critical of this approach is that designing a secure hybrid protocol. In this paper, we study password-based key exchange in the three-party setting within the UC framework and design a hybrid protocol that UC-securely realizes such task. That is, we firstly define an appropriate ideal functionality F3-pwKE for password-based three-party key exchange. Next we partition the task into two sub-tasks, three-party key distribution and password-based two-party key exchange, and propose relevant two ideal functionalities, F3-KD, FpwKE. Finally, we present a (F3-KD, FpwKE)-hybrid protocol for password-based three-party key exchange that is proved to be UC-secure with respect to non- adaptive party corruption.

Nicanfar and Leung proposed a multilayer consensus elliptic curve based password authenticated key-exchange (MCEPAK) protocol for smart grid. They claimed that their protocol is secure against possible attacks. In this paper, we show that the MCEPAK protocol is vulnerable to the dictionary attack and an adversary can obtain the passwords of the appliances by eavesdropping the communicated messages in the protocol. Moreover, we state that the passwords can be discovered by curious operators of the building area networks and the neighbor area networks. Theses weaknesses motivated us to introduce a chaotic maps based authenticated key exchange protocol for smart grid. To the best of our knowledge, the chaotic maps based key exchange protocol has not yet been devised for smart grid and the same objective has been fulfilled in this paper. In addition, we prove the security of the proposed protocol by a formal analysis.

In three-party password authenticated key exchange (AKE) protocol, since two users use their passwords to establish a secure session key over an insecure communication channel with the help of the trusted server, such a protocol may suffer the password guessing attacks and the server has to maintain the password table. To eliminate the shortages of password-based AKE protocol, very recently, according to chaotic maps, Lee et al. [2015 Nonlinear Dyn. 79 2485] proposed a first three-party-authenticated key exchange scheme without using passwords, and claimed its security by providing a well-organized BAN logic test. Unfortunately, their protocol cannot resist impersonation attack, which is demonstrated in the present paper. To overcome their security weakness, by using chaotic maps, we propose a biometrics-based anonymous three-party AKE protocol with the same advantages. Further, we use the pi calculus-based formal verification tool ProVerif to show that our AKE protocol achieves authentication, security and anonymity, and an acceptable efficiency.

Cryptographic Primitives that Resist Backdooring and Subversion

The main problem associated with using symmetric/ asymmetric keys is how to securely store and exchange the keys between the parties over open networks particularly in the open environment such as cloud computing. Public Key Infrastructure (PKI) have been providing a practical solution for session key exchange for loads of web services. The key limitation of PKI solution is not only the need for a trusted third partly (e.g. certificate authority) but also the absent link between data owner and the encryption keys. The latter is arguably more important where accessing data needs to be linked with identify of the owner. Currently available key exchange protocols depend on using trusted couriers or secure channels, which can be subject to man-in-the-middle attack and various other attacks. This paper proposes a new protocol for Key Exchange using Biometric Identity Based Encryption (KE-BIBE) that enables parties to securely exchange cryptographic keys even an adversary is monitoring the communication channel between the parties. The proposed protocol combines biometrics with IBE in order to provide a secure way to access symmetric keys based on the identity of the users in unsecure environment. In the KE-BIOBE protocol, the message is first encrypted by the data owner using a traditional symmetric key before migrating it to a cloud storage. The symmetric key is then encrypted using public biometrics of the users selected by data owner to decrypt the message based on Fuzzy Identity-Based Encryption. Only the selected users will be able to decrypt the message by providing a fresh sample of their biometric data. The paper argues that the proposed solution eliminates the needs for a key distribution centre in traditional cryptography. It will also give data owner the power of finegrained sharing of encrypted data by control who can access their data.

A Lightweight Leakage-Resilient Identity-Based Mutual Authentication and Key Exchange Protocol for Resource-limited Devices

Three-party password-based authenticated key exchange (3-party PAKE) protocols make two communication parties establish a shared session key with the help of a trusted server, with which each of the two parties shares a predetermined password. Recently, with the first formal treatment for 3-party PAKE protocols addressed by Abdalla et al., the security of such protocols has received much attention from cryptographic protocol researchers. In this paper, we consider the security of 3-party PAKE protocols against undetectable on-line dictionary attacks which are serious and covert threats for the protocals. We examine two 3-party PAKE schemes proposed recently by Abdalla et al. and reveal their common weakness in resisting undetectable on-line dictionary attacks. With reviewing the formal model for 3-party PAKE protocols of Abdalla et al. and enhancing it by adding the authentication security notion for the treatment of undetectable attacks, we then present an efficient generic construction for 3-party PAKE protocols, and prove it enjoys both the semantic security and the authentication security.

Diffie-Hellman (D-H) key exchange protocol, first published in 1976 is one of the most distinguished and widely used secured key exchange protocols. The protocol makes it possible to exchange a symmetric key between two parties over an unsecured communication channel without pre-agreement of any shared secret. The D-H key exchange protocol however requires a pre-set public parameters P (a large prime) and g a generator of ℤp to be public i.e. known to all users of the system. This paper proposes a key exchange mechanism without any public parameter. Unlike D-H key exchange mechanism our scheme uses encryption to transmit intermediate data during key exchange stage, thus it is non-vulnerable to man-in-the-middle attach.

A revocable ID-based authenticated group key exchange protocol with resistant to malicious participants

A three-party password-based authenticated key exchange (PAKE) protocol allows two clients registered with a trusted server to generate a common cryptographic key from their individual passwords shared only with the server. A key requirement for three-party PAKE protocols is to prevent an adversary from mounting a dictionary attack. This requirement must be met even when the adversary is a malicious (registered) client who can set up normal protocol sessions with other clients. This work revisits three existing three-party PAKE protocols, namely, Guo et al.’s (2008) protocol, Huang’s (2009) protocol, and Lee and Hwang’s (2010) protocol, and demonstrates that these protocols are not secure against offline and/or (undetectable) online dictionary attacks in the presence of a malicious client. The offline dictionary attack we present against Guo et al.’s protocol also applies to other similar protocols including Lee and Hwang’s protocol. We conclude with some suggestions on how to design a three-party PAKE protocol that is resistant against dictionary attacks.