1,287 research outputs found
Security of two recent constant-round password authenticated group key exchange schemes
When humans interact with machines in their daily networks, it is important that security of the communications is offered, and where the involved shared secrets used to achieve this are easily remembered by humans. Password-based authenticated group key exchange (PAGKE) schemes allow group users to share a session key based on a human-memorizable password. In this paper, we consider two PAGKE schemes that build on the seminal scheme of Burmester and Desmedt. Weshow an undetectable online dictionary attack on the first scheme, and exploit the partnering definition to break the key indistinguishability of the second scheme
Structure-Preserving Smooth Projective Hashing
International audienceSmooth projective hashing has proven to be an extremely useful primitive, in particular when used in conjunction with commitments to provide implicit decommitment. This has lead to applications proven secure in the UC framework, even in presence of an adversary which can do adaptive corruptions, like for example Password Authenticated Key Exchange (PAKE), and 1-out-of-m Oblivious Transfer (OT). However such solutions still lack in efficiency, since they heavily scale on the underlying message length. Structure-preserving cryptography aims at providing elegant and efficient schemes based on classical assumptions and standard group operations on group elements. Recent trend focuses on constructions of structure- preserving signatures, which require message, signature and verification keys to lie in the base group, while the verification equations only consist of pairing-product equations. Classical constructions of Smooth Projective Hash Function suffer from the same limitation as classical signatures: at least one part of the computation (messages for signature, witnesses for SPHF) is a scalar. In this work, we introduce and instantiate the concept of Structure- Preserving Smooth Projective Hash Function, and give as applications more efficient instantiations for one-round PAKE and three-round OT, and information retrieval thanks to Anonymous Credentials, all UC- secure against adaptive adversaries
Authentication and Key Management Automation in Decentralized Secure Email and Messaging via Low-Entropy Secrets
We revisit the problem of entity authentication in decentralized end-to-end encrypted email and secure messaging to propose a practical and self-sustaining cryptographic solution based on
password-authenticated key exchange (PAKE). This not only allows users to authenticate each other via shared low-entropy secrets, e.g., memorable words, without a public key infrastructure or a trusted third party, but it also paves the way for automation and a series of cryptographic enhancements; improves security by minimizing the impact of human error and potentially improves usability. First, we study a few vulnerabilities in voice-based out-of-band authentication, in particular a combinatorial attack against lazy users, which we analyze in the context of a secure email solution. Next, we propose solving the problem of secure equality test using PAKE to achieve entity authentication and to establish a shared high-entropy secret key. Our solution lends itself to offline settings, compatible with the inherently asynchronous nature of email and modern messaging systems. The suggested approach enables enhancements in key management such as automated key renewal and future key pair authentications, multi-device synchronization, secure secret storage and retrieval, and the possibility of post-quantum security as well as facilitating forward secrecy and deniability in a primarily symmetric-key setting. We also discuss the use of auditable PAKEs for mitigating a class of online guess and abort attacks in authentication protocols
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MobileTrust: Secure Knowledge Integration in VANETs
Vehicular Ad hoc NETworks (VANET) are becoming popular due to the emergence of the Internet of Things and ambient intelligence applications. In such networks, secure resource sharing functionality is accomplished by incorporating trust schemes. Current solutions adopt peer-to-peer technologies that can cover the large operational area. However, these systems fail to capture some inherent properties of VANETs, such as fast and ephemeral interaction, making robust trust evaluation of crowdsourcing challenging. In this article, we propose MobileTrust—a hybrid trust-based system for secure resource sharing in VANETs. The proposal is a breakthrough in centralized trust computing that utilizes cloud and upcoming 5G technologies to provide robust trust establishment with global scalability. The ad hoc communication is energy-efficient and protects the system against threats that are not countered by the current settings. To evaluate its performance and effectiveness, MobileTrust is modelled in the SUMO simulator and tested on the traffic features of the small-size German city of Eichstatt. Similar schemes are implemented in the same platform to provide a fair comparison. Moreover, MobileTrust is deployed on a typical embedded system platform and applied on a real smart car installation for monitoring traffic and road-state parameters of an urban application. The proposed system is developed under the EU-founded THREAT-ARREST project, to provide security, privacy, and trust in an intelligent and energy-aware transportation scenario, bringing closer the vision of sustainable circular economy
On the Use of Key Assignment Schemes in Authentication Protocols
Key Assignment Schemes (KASs) have been extensively studied in the context of
cryptographically-enforced access control, where derived keys are used to
decrypt protected resources. In this paper, we explore the use of KASs in
entity authentication protocols, where we use derived keys to encrypt
challenges. This novel use of KASs permits the efficient authentication of an
entity in accordance with an authentication policy by associating entities with
security labels representing specific services. Cryptographic keys are
associated with each security label and demonstrating knowledge of an
appropriate key is used as the basis for authentication. Thus, by controlling
the distribution of such keys, restrictions may be efficiently placed upon the
circumstances under which an entity may be authenticated and the services to
which they may gain access.
In this work, we explore how both standardized protocols and novel
constructions may be developed to authenticate entities as members of a group
associated to a particular security label, whilst protecting the long-term
secrets in the system. We also see that such constructions may allow for
authentication whilst preserving anonymity, and that by including a trusted
third party we can achieve the authentication of individual identities and
authentication based on timestamps without the need for synchronized clocks
Secure Chaotic Maps-based Group Key Agreement Scheme with Privacy Preserving
Abstract Nowadays chaos theory related to cryptography has been addressed widely, so there is an intuitive connection between group key agreement and chaotic maps. Such a connector may lead to a novel way to construct authenticated and efficient group key agreement protocols. Many chaotic maps based two-party/three-party password authenticated key agreement (2PAKA/3PAKA) schemes have been proposed. However, to the best of our knowledge, no chaotic maps based group (N-party) key agreement protocol without using a timestamp and password has been proposed yet. In this paper, we propose the first chaotic maps-based group authentication key agreement protocol. The proposed protocol is based on chaotic maps to create a kind of signcryption method to transmit authenticated information and make the calculated consumption and communicating round restrict to an acceptable bound. At the same time our proposed protocol can achieve members' revocation or join easily, which not only refrains from consuming modular exponential computing and scalar multiplication on an elliptic curve, but is also robust to resist various attacks and achieves perfect forward secrecy with privacy preserving
Security and Privacy Issues in Wireless Mesh Networks: A Survey
This book chapter identifies various security threats in wireless mesh
network (WMN). Keeping in mind the critical requirement of security and user
privacy in WMNs, this chapter provides a comprehensive overview of various
possible attacks on different layers of the communication protocol stack for
WMNs and their corresponding defense mechanisms. First, it identifies the
security vulnerabilities in the physical, link, network, transport, application
layers. Furthermore, various possible attacks on the key management protocols,
user authentication and access control protocols, and user privacy preservation
protocols are presented. After enumerating various possible attacks, the
chapter provides a detailed discussion on various existing security mechanisms
and protocols to defend against and wherever possible prevent the possible
attacks. Comparative analyses are also presented on the security schemes with
regards to the cryptographic schemes used, key management strategies deployed,
use of any trusted third party, computation and communication overhead involved
etc. The chapter then presents a brief discussion on various trust management
approaches for WMNs since trust and reputation-based schemes are increasingly
becoming popular for enforcing security in wireless networks. A number of open
problems in security and privacy issues for WMNs are subsequently discussed
before the chapter is finally concluded.Comment: 62 pages, 12 figures, 6 tables. This chapter is an extension of the
author's previous submission in arXiv submission: arXiv:1102.1226. There are
some text overlaps with the previous submissio
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