23,906 research outputs found
A Practical Set-Membership Proof for Privacy-Preserving NFC Mobile Ticketing
To ensure the privacy of users in transport systems, researchers are working
on new protocols providing the best security guarantees while respecting
functional requirements of transport operators. In this paper, we design a
secure NFC m-ticketing protocol for public transport that preserves users'
anonymity and prevents transport operators from tracing their customers' trips.
To this end, we introduce a new practical set-membership proof that does not
require provers nor verifiers (but in a specific scenario for verifiers) to
perform pairing computations. It is therefore particularly suitable for our
(ticketing) setting where provers hold SIM/UICC cards that do not support such
costly computations. We also propose several optimizations of Boneh-Boyen type
signature schemes, which are of independent interest, increasing their
performance and efficiency during NFC transactions. Our m-ticketing protocol
offers greater flexibility compared to previous solutions as it enables the
post-payment and the off-line validation of m-tickets. By implementing a
prototype using a standard NFC SIM card, we show that it fulfils the stringent
functional requirement imposed by transport operators whilst using strong
security parameters. In particular, a validation can be completed in 184.25 ms
when the mobile is switched on, and in 266.52 ms when the mobile is switched
off or its battery is flat
Enabling Privacy-preserving Auctions in Big Data
We study how to enable auctions in the big data context to solve many
upcoming data-based decision problems in the near future. We consider the
characteristics of the big data including, but not limited to, velocity,
volume, variety, and veracity, and we believe any auction mechanism design in
the future should take the following factors into consideration: 1) generality
(variety); 2) efficiency and scalability (velocity and volume); 3) truthfulness
and verifiability (veracity). In this paper, we propose a privacy-preserving
construction for auction mechanism design in the big data, which prevents
adversaries from learning unnecessary information except those implied in the
valid output of the auction. More specifically, we considered one of the most
general form of the auction (to deal with the variety), and greatly improved
the the efficiency and scalability by approximating the NP-hard problems and
avoiding the design based on garbled circuits (to deal with velocity and
volume), and finally prevented stakeholders from lying to each other for their
own benefit (to deal with the veracity). We achieve these by introducing a
novel privacy-preserving winner determination algorithm and a novel payment
mechanism. Additionally, we further employ a blind signature scheme as a
building block to let bidders verify the authenticity of their payment reported
by the auctioneer. The comparison with peer work shows that we improve the
asymptotic performance of peer works' overhead from the exponential growth to a
linear growth and from linear growth to a logarithmic growth, which greatly
improves the scalability
Pendekatan konstruktif dalam inovasi pengajaran dan pembelajaran Bahasa Melayu di Kolej Vokasional
Pendekatan konstruktif adalah pendekatan pengajaran dan pembelajaran yang
berpusatkan pelajar manakala inovasi pengajaran pula dikaitkan dengan kaedah
pengajaran yang terbaru demi mengukuhkan pemahaman pelajar. Pembelajaran
berasaskan pendekatan konstruktif merupakan elemen yang penting dan perlu
difahami oleh guru-guru bagi memantapkan proses pengajaran dan pembelajaran
sesuai dengan peredaran masa dan menjayakan proses tranformasi pendidikan
negara. Objektif kajian ini dijalankan untuk mengenal pasti pemahaman guru-guru
bahasa Melayu berkaitan inovasi, mengenal pasti perbezaan yang wujud antara guru
lelaki dan guru perempuan dalam mengamalkan inovasi, pengkaji juga melihat
adakah wujud perbezaan antara guru baru dan guru yang sudah berpengalaman
dalam aspek mengaplikasikan inovasi serta mengenal pasti kekangan-kekangan yang
dialami oleh para guru untuk mengaplikasikan inovasi di sekolah. Seramai 63 orang
guru bahasa Melayu dari lapan buah kolej vokasional telah dipilih sebagai responden
dalam kajian ini. Data dianalisis menggunakan perisian Winsteps 3.69.1.11 dengan
pendekatan Model Pengukuran Rasch. Hasil analisis menunjukkan bahawa guru�guru bahasa Melayu memahami kepentingan inovasi dalam pengajaran dan
pembelajaran. Hasil kajian juga menunjukkan guru-guru perempuan lebih banyak
menerapkan unsur inovasi dalam pengajaran berbanding guru lelaki. Walaupun
begitu, aspek pengalaman tidak menunjukkan perbezaan dari segi pengamalan
inovasi sama ada guru baru ataupun guru yang sudah berpengalaman. Pengkaji juga
mengenal pasti beberapa kekangan yang dialami oleh guru-guru untuk mengamalkan
inovasi ini. Sebagai langkah untuk menangani masalah berkenaan, beberapa
cadangan telah dikemukakan oleh pengkaji bagi memastikan guru-guru dapat
merealisasikan proses pengajaran berkesan dengan penerapan inovasi mengikut
model pendekatan konstruktif. Pengkaji berharap, kajian ini dapat dijadikan sebagai
satu panduan kepada pelaksana kurikulum bagi memastikan budaya inovasi sentiasa
menjadi amalan dalam kalangan guru demi mengangkat profesionalisme guru di
Malaysia
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
Migration control for mobile agents based on passport and visa
Research on mobile agents has attracted much attention as this paradigm has demonstrated great potential for the next-generation e-commerce. Proper solutions to security-related problems become key factors in the successful deployment of mobile agents in e-commerce systems. We propose the use of passport and visa (P/V) for securing mobile agent migration across communities based on the SAFER e-commerce framework. P/V not only serves as up-to-date digital credentials for agent-host authentication, but also provides effective security mechanisms for online communities to control mobile agent migration. Protection for mobile agents, network hosts, and online communities is enhanced using P/V. We discuss the design issues in details and evaluate the implementation of the proposed system
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Integrity protection for code-on-demand mobile agents in e-commerce
The mobile agent paradigm has been proposed as a promising solution to facilitate distributed computing over open and heterogeneous networks. Mobility, autonomy, and intelligence are identified as key features of mobile agent systems and enabling characteristics for the next-generation smart electronic commerce on the Internet. However, security-related issues, especially integrity protection in mobile agent technology, still hinder the widespread use of software agents: from the agent’s perspective, mobile agent integrity should be protected against attacks from malicious hosts and other agents. In this paper, we present Code-on-Demand(CoD) mobile agents and a corresponding agent integrity protection scheme. Compared to the traditional assumption that mobile agents consist of invariant code parts, we propose the use of dynamically upgradeable agent code, in which new agent function modules can be added and redundant ones can be deleted at runtime. This approach will reduce the weight of agent programs, equip mobile agents with more flexibility, enhance code privacy and help the recoverability of agents after attack. In order to meet the security challenges for agent integrity protection, we propose agent code change authorization protocols and a double integrity verification scheme. Finally, we discuss the Java implementation of CoD mobile agents and integrity protection
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