An improved password-authenticated key exchange protocol for VANET

Password-authenticated key exchange (PAKE) protocols tackle the important problem of how to enable two parties, who share a low-entropy password, to establish a cryptographically strong session key for secure data communication. Although considerable research efforts have been devoted to designing hundreds of PAKE protocols, to the best of our knowledge, there have been few systematic reviews. In this work, we provide a comprehensive overview of PAKE research. We first propose a list of 13 desirable properties of PAKE protocols in terms of security and usability, enabling PAKE protocols to be systematically rated across a common spectrum. We then provide a taxonomy for PAKE protocols, and classify them into seven types according to their underlying design strategies. For each type, we investigate the inner working mechanisms of various representative protocols, and identify their pros, and cons. We further classify existing PAKE protocols from five other key perspectives (i.e., symmetry, number of participants, hardness assumptions, security goals, and round complexity) and review their development history under each classification, aiming to provide an in-depth and thorough understanding of the status quo of PAKE research. Based on 13 properties and six perspectives, we conduct a large-scale comparative evaluation of 71 representative PAKE protocols in a systematic manner. Finally, we highlight a few potential directions for the future design of PAKE protocols.

A password-authenticated key exchange (PAKE) protocol allows two entities sharing a password to perform mutual authentication and establish a session key. Benefiting from the use of a low-entropy human-memorable password, PAKE avoids the use of PKI in the authentication process, making it more flexible and cheaper. However, with the development of quantum computing, protocols based on classical assumptions will no longer be secure, so designing a PAKE protocol capable of resisting quantum attacks has become an important research direction. In this work, we propose an efficient PAKE protocol using a new error reconciliation mechanism based on the ring learning with errors (RLWE) problem, which is considered to resist quantum attacks. Our protocol is proven security under the Bellare-Pointcheval-Rogaway (BPR) model. The protocol is implemented using the C language, which is highly portable, and is also optimized utilizing the Advanced Vector Extensions 2 (AVX2) instruction set. Compared with the C implementation of Ding’s protocol, our reference C implementation is more than 12x faster, and the efficiency is doubled after AVX2 optimization. Moreover, by choosing the appropriate parameters, the security strength of our scheme is improved and the message size is reduced.

Password-Authenticated Key Exchange (PAKE) protocols allow parties to share secret keys in an authentic manner based on an easily memorizable password. Recently, Nam et al. showed that a provably secure three-party password-based authenticated key exchange protocol using Weil pairing by Wen et al. is vulnerable to a man-in-the-middle attack. In doing so, Nam et al. showed the flaws in the proof of Wen et al. and described how to fix the problem so that their attack no longer works. In this paper, we show that both Wen et al. and Nam et al. variants fall to key compromise impersonation by any adversary. Our results underline the fact that although the provable security approach is necessary to designing PAKEs, gaps still exist between what can be proven and what are really secure in practice.

We analyze the Secure Remote Password (SRP) protocol for structural weaknesses using the Cryptographic Protocol Shapes Analyzer (CPSA) in the first formal analysis of SRP (specifically, Version 3).SRP is a widely deployed Password Authenticated Key Exchange (PAKE) protocol used in 1Password, iCloud Keychain, and other products. As with many PAKE protocols, two participants use knowledge of a pre-shared password to authenticate each other and establish a session key. SRP aims to resist dictionary attacks, not store plaintext-equivalent passwords on the server, avoid patent infringement, and avoid export controls by not using encryption. Formal analysis of SRP is challenging in part because existing tools provide no simple way to reason about its use of the mathematical expression \(v + g^b \mod q\).Modeling \(v + g^b\) as encryption, we complete an exhaustive study of all possible execution sequences of SRP. Ignoring possible algebraic attacks, this analysis detects no major structural weakness, and in particular no leakage of any secrets. We do uncover one notable weakness of SRP, which follows from its design constraints. It is possible for a malicious server to fake an authentication session with a client, without the client’s participation. This action might facilitate an escalation of privilege attack, if the client has higher privileges than does the server. We conceived of this attack before we used CPSA and confirmed it by generating corresponding execution shapes using CPSA.KeywordsCryptographic protocolsCryptographyCryptographic Protocol Shapes Analyzer (CPSA)CybersecurityFormal methodsPassword Authenticated Key Exchange (PAKE) protocolsProtocol analysisSecure Remote Protocol (SRP)UMBC Protocol Analysis Lab (PAL)

In recent years, many password authenticated key exchange (PAKE) protocols have been proposed. However, many of them have been broken or have no security proof. In this paper, we propose an efficient password authenticated key exchange protocol using bilinear pairings. Compared with previous PAKE protocol using bilinear pairings, our protocol is quite efficient both in communication cost and computational cost. Moreover, this paper proves that the novel protocol is forward secrecy under the Bilinear Diffie-Hellman (BDH) assumption in the random oracle model.KeywordsPAKEbilinear paringBDHforward secrecy

With the popularity of unmanned aerial vehicles (UAVs), more and more valuable data can be collected by UAVs. In order to balance the data usage and communication cost, the data can be preprocessed in UAVs rather than directly transmitting to the data centre in the edge computing paradigm. Users can obtain information of interest by accessing the data centre remotely by authenticating themselves to the data centre using the most pervasive password authentication method. Unfortunately, the data centre becomes the main attack target because it not only stores the data but also maintains the passwords of all the users. Aiming at protecting the data as well as the password in the UAV‐enabled mobile edge computing environment, the authors combine the advantages of gateway‐oriented password authenticated key exchange (PAKE) protocols and two‐server PAKE protocols and put forward an efficient gateway‐oriented two‐server PAKE protocol. The security of the proposed protocol is given in the random oracle model. The performance comparison shows their proposal has comparable efficiency in computation and communication costs. Their protocol provides better protection to the password without sacrificing efficiency. Consequently, their protocol is more suitable for real applications in UAV‐enabled mobile edge computing environment.

Authentication has been a cornerstone of computer security for decades. A considerable number of authentication protocols have been specified and implemented. This paper compares most common families of client-server authentication protocols and shows the benefits of the combined use of One Time Password (OTP) with Password Authenticated Key Exchange (PAKE) protocols. Then, the paper addresses a particular issue inherited from this combination which consists in the synchronization between the client and the server. We propose an optimized implementation for a synchronization mechanism based on the use of a synchronization window. The optimized synchronization has been implemented and the simulation results show that our proposal significantly reduces the computations needed at the client side to select the current password.

The area of password-based authenticated key exchange protocols has been the subject of a vast amount of work in the last few years due to its practical aspects. AuthA is an example of such a technology considered for standardization by the IEEE P1363.2 working group. Unfortunately in its current form AuthA, including some variants, only considered the classic client and server (2-party) scenarios. In this paper, based on a variant of AuthA, we consider a quite different paradigm from the existing ones and propose a provably secure password-authenticated key exchange protocol in a cross-realm setting where two clients in different realms obtain a secret session key as well as mutual authentication, with the help of respective servers. In our protocol, any honest server is unable to gain any information on the value of that session key. Moreover, our protocol is reasonably efficient and has a per-user computational cost that is comparable to that of the underlying 2-party encrypted key exchange.

This paper explains the sync problem and compares solutions in Firefox 4 and Chrome 10. The sync problem studies how to securely synchronize data across different computers. Google has added a built-in sync function in Chrome 10, which uses a user-defined password to encrypt bookmarks, history, cached passwords etc. However, due to the low-entropy of passwords, the encryption is inherently weak --- anyone with access to the ciphertext can easily uncover the key (and hence disclose the plaintext). Mozilla used to have a very similar sync solution in Firefox 3.5, but since Firefox 4 it has made a complete change of how sync works in the browser. The new solution is based on a security protocol called J-PAKE, which is a balanced Password Authenticated Key Exchange (PAKE) protocol. To our best knowledge, this is the first large-scale deployment of the PAKE technology. Since PAKE does not require a PKI, it has compelling advantages than PKI-based schemes such as SSL/TLS in many applications. However, in the past decade, deploying PAKE has been greatly hampered by the patent and other issues. With the rise of patent-free solutions such as J-PAKE and also that the EKE patent will soon expire in October, 2011, we believe the PAKE technology will be more widely adopted in the near future.

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

There have been many proposals in recent years for password-authenticated key exchange protocols.Man y of these have been shown to be insecure, and the only ones that seemed likely to be proven secure (against active adversaries who may attempt to perform off-line dictionary attacks against the password) were based on the Diffie-Hellman problem. In fact, some protocols based on Diffie-Hellman have been recently proven secure in the random-oracle model. We examine how to design a provably-secure password-authenticated key exchange protocol based on RSA.We first look at the OKE and protected-OKE protocols (both RSA-based) and show that they are insecure.Then we show how to modify the OKE protocol to obtain a password-authenticated key exchange protocol that can be proven secure (in the random oracle model). The resulting protocol is very practical; in fact the basic protocol requires about the same amount of computation as the Diffie-Hellman-based protocols or the well-known ssh protocol.

In this paper, we cryptanalyze the recent smart card based client-to-client password-authenticated key agreement (C2C-PAKA-SC) protocol for cross-realm settings proposed at CANS ’09. While client-to-client password-authenticated key exchange (C2C-PAKE) protocols exist in literature, what is interesting about this one is that it is the only such protocol claimed to offer security against password compromise impersonation without depending on public-key cryptography, and is one of the few C2C-PAKE protocols with provable security that has not been cryptanalyzed. We present three impersonation attacks on this protocol; the first two are easier to mount than the designer-considered password compromise impersonation. Our results are the first known cryptanalysis results on C2C-PAKA-SC.KeywordsClient-to-clientpassword-authenticated key agreementcross realmimpersonationattack

It is universally acknowledged that Wi-Fi communications are important to secure. Thus, the Wi-Fi Alliance published WPA3 in 2018 with a distinctive security feature: it leverages a Password-Authenticated Key Exchange (PAKE) protocol to protect users’ passwords from offline dictionary attacks. Unfortunately, soon after its release, several attacks were reported against its implementations, in response to which the protocol was updated in a best-effort manner.In this paper, we show that the proposed mitigations are not enough, especially for a complex protocol to implement even for savvy developers. Indeed, we present Dragondoom, a collection of side-channel vulnerabilities of varying strength allowing attackers to recover users’ passwords in widely deployed Wi-Fi daemons, such as hostap in its default settings. Our findings target both password conversion methods, namely the default probabilistic hunting-and-pecking and its newly standardized deterministic alternative based on SSWU. We successfully exploit our leakage in practice through microarchitectural mechanisms, and overcome the limited spatial resolution of Flush+Reload. Our attacks outperform previous works in terms of required measurements.Then, driven by the need to end the spiral of patch-and-hack in Dragonfly implementations, we propose Dragonstar, an implementation of Dragonfly leveraging a formally verified implementation of the underlying mathematical operations, thereby removing all the related leakage vector. Our implementation relies on HACL*, a formally verified crypto library guaranteeing secret-independence. We design Dragonstar, so that its integration within hostap requires minimal modifications to the existing project. Our experiments show that the performance of HACL*-based hostap is comparable to OpenSSL-based, implying that Dragonstar is both efficient and proved to be leakage-free.

For enhancing the security of ubiquitous communication, we have to consider three keywords: mobility, wireless, and low computing capability. In this paper, we study one of suitable security protocols for the ubiquitous communication environment. We discuss RSA-based password-authenticated key exchange (RSA-PAKE) protocols for imbalanced wireless networks where a party uses a low-power device to communicate with another party equipped with a powerful computing device. For imbalanced wireless network applications, it is important to reduce the cost of communication for a low-power device even though the cost for powerful devices is increasing. The most power-consuming operation in RSA-PAKE protocols is the reliability test of unauthorized RSA public keys. Hence, it is important to design an efficient reliability test method to construct an efficient RSA-PAKE protocol. In this paper, we propose a new reliability test technique and design a provably secure RSA-PAKE protocol using the technique. Our protocol is suitable for securing the communications conducted over imbalanced wireless networks since the operations computed by one communicating party are efficient enough to be implemented on most low-power devices such as mobile phones and PDAs. The cost of a low-power device is reduced by 84.25% compared with CEKEP, the most efficient RSA-PAKE protocol. We prove the security of our protocol under a firmly formalized security model.

Three-party password authenticated key exchange protocol is a very practical mechanism to establish secure session key through authenticating each other with the help of a trusted server. Based on certificateless key encapsulation mechanism, we present a specific three-party password authenticated key exchange protocol under DDH assumption. Security analysis showed that the proposed protocol could fulfill all the necessary security requirements.