Browsing by Author "Ren, Wei"

Now showing 1 - 9 of 9

A Robust and Flexible Access Control Scheme for Cloud-IoT Paradigm with Application to Remote Mobile Medical Monitoring
(2015)
Ren, Wei
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Ren, Yi
;
Wu, Mu-En
;
Lee, Chia-Jung
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資訊工程學系
Cloud computing paradigm is becoming very popular these days. However, it does not include wireless sensors and mobile phones which are needed to enable new emerging applications such as remote home medical monitoring. Therefore, a combined Cloud-Internet of Things (IoT) paradigm provides scalable on-demand data storage and resilient computation power at the cloud side as well as anytime, anywhere health data monitoring at the IoT side. As both the privacy of personal medical data and flexible data access should be provided, the data in the Cloud are always encrypted and access control must be operated upon encrypted data together with being fine-grained to support diverse accessibility. Since a plain combination of encryption before access control is not robust and flexible, we propose a scheme with tailored design. The scheme makes use of cipher-policy attributes based encryption to empower robustness and flexibility. The scheme describes a general framework to solve the secure requirements, and leaves the flexibility of concrete constructions intentionally.
APP: An Ultralightweight Scheme to Authenticate ONS and Protect EPC Privacy without Cryptography in EPCglobal Networks
(2013)
Ren, Wei
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Ma, Liangli
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Ren, Yi
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資訊工程學系
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Department of Computer Science
EPCglobal network is used to share product data between trading partners, which was proposed by EPCglobal. Object Name Service (ONS) in EPCglobal framework raises two critical security risks: the authenticity of IP addresses for Physical Markup Language (PML) servers and the privacy of Electronic Product Codes (EPCs). Existing work considers either the IP address authentication or the EPC privacy. In addition, that work mainly relies on cryptographic tools, in which key distribution is not a trivial task and also causes a large amount of computation overhead. In this paper, we make the first attempt to solve those two security risks together without relying cryptography. We propose a scheme, namely, APP (authenticate ONS and protect EPC privacy), to guarantee the authenticity of IP addresses for PML servers as well as EPC privacy and to maintain ultralightweight computation cost. Moreover, we give formal definition of the authenticity and the privacy in ONS context. The security achievements are strictly analyzed and proved. The extensive analysis results justify the applicability of the proposed scheme.
Enhanced electric conductivity at ferroelectric vortex cores in BiFeO(3)
(2012-01-01)
Balke, Nina
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Winchester, Benjamin
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Ren, Wei
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Chu, Ying Hao
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Morozovska, Anna N.
Topological defects in ferroic materials are attracting much attention both as a playground of unique physical phenomena and for potential applications in reconfigurable electronic devices. Here, we explore electronic transport at artificially created ferroelectric vortices in BiFeO(3) thin films. The creation of one-dimensional conductive channels activated at voltages as low as 1V is demonstrated. We study the electronic as well as the static and dynamic polarization structure of several topological defects using a combination of first-principles and phase-field modelling. The modelling predicts that the core structure can undergo a reversible transformation into a metastable twist structure, extending charged domain walls segments through the film thickness. The vortex core is therefore a dynamic conductor controlled by the coupled response of polarization and electron-mobile-vacancy subsystems with external bias. This controlled creation of conductive one-dimensional channels suggests a pathway for the design and implementation of integrated oxide electronic devices based on domain patterning.
Enhanced electric conductivity at ferroelectric vortex cores in BiFeO3
(2012-01-01)
Balke, Nina
;
Winchester, Benjamin
;
Ren, Wei
;
Chu, Ying Hao
;
Morozovska, Anna N.
Topological defects in ferroic materials are attracting much attention both as a playground of unique physical phenomena and for potential applications in reconfigurable electronic devices. Here, we explore electronic transport at artificially created ferroelectric vortices in BiFeO3 thin films. The creation of one-dimensional conductive channels activated at voltages as low as 1V is demonstrated. We study the electronic as well as the static and dynamic polarization structure of several topological defects using a combination of first-principles and phase-field modelling. The modelling predicts that the core structure can undergo a reversible transformation into a metastable twist structure, extending charged domain walls segments through the film thickness. The vortex core is therefore a dynamic conductor controlled by the coupled response of polarization and electron-mobile-vacancy subsystems with external bias. This controlled creation of conductive one-dimensional channels suggests a pathway for the design and implementation of integrated oxide electronic devices based on domain patterning.
How to Authenticate a Device? Formal Authentication Models for M2M Communications Defending against Ghost Compromising Attack
(2013)
Ren, Wei
;
Yu, Linchen
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Ma, Liangli
;
Ren, Yi
;
資訊工程學系
In Machine-to-Machine (M2M) communications, authentication of a device is of upmost importance for applications of Internet of Things. As traditional authentication schemes always assume the presence of a person, most authentication technologies cannot be applied in machine-centric M2M context. In this paper, we make the first attempt to formally model the authentication in M2M. We first model four attacking adversaries that can formulate all possible attacks in M2M, which are channel eavesdropping attack, credential compromise attack, function compromise attack, and ghost compromise attack. Next, we propose four models to tackle those corresponding adversaries, namely, credential-based model, machine-metrics-based model, reference-based model, and witness-based model. We also illustrate several concrete attacking methods and authentication approaches. We proof the authentication security for all proposed models and compare them for clarity. Our models present soundness and completeness in terms of authentication security, which can guide the design and analysis of concrete authentication protocols. Particularly, we construct a uniform authentication framework for M2M context and point out all possible authentication mechanisms in M2M.
LiPISC: A Lightweight and Flexible Method for Privacy-Aware Intersection Set Computation
(2016-06-21)
Ren, Wei
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Huang, Shiyong
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Ren, Yi
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Choo, Kim-Kwang Raymond
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資訊工程學系
Privacy-aware intersection set computation (PISC) can be modeled as secure multi-party computation. The basic idea is to compute the intersection of input sets without leaking privacy. Furthermore, PISC should be sufficiently flexible to recommend approximate intersection items. In this paper, we reveal two previously unpublished attacks against PISC, which can be used to reveal and link one input set to another input set, resulting in privacy leakage. We coin these as Set Linkage Attack and Set Reveal Attack. We then present a lightweight and flexible PISC scheme (LiPISC) and prove its security (including against Set Linkage Attack and Set Reveal Attack).
LIRT: A Lightweight Scheme for Indistinguishability, Reachability, and Timeliness in Wireless Sensor Control Networks
(2013)
Ren, Wei
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Ma, Liangli
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Ren, Yi
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資訊工程學系
;
Department of Computer Science
Wireless sensor control networks (WSCNs) are important scenarios and trends in mobile wireless sensor networks. Compared with traditional wireless sensor networks, WSCNs have two specific characteristics: entities in networks are extended from passive sensors to active sensors (e.g., actuators and actors) and the transmitting messages are extended from data only to data plus (e. g., data and control instructions). Thus new security problems arises. In this paper, we make the first attempt to specify the security requirements for WSCNs, namely, indistinguishability, reachability, and timeliness. In addition, several new attacks in WSCN, distinguishing risks, dropping attacks, and disordering attacks, are pointed out at the first time. A lightweight scheme LIRT is proposed with tailored design to guarantee the indistinguishability, reachability, and timeliness in WSCNs. Extensive and rigorous analysis on LIRT justifies its security strength and performance measures.
Perturbation-Based Schemes with Ultra-Lightweight Computation to Protect User Privacy in Smart Grid
(2013)
Ren, Wei
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Ma, Liangli
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Ren, Yi
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資訊工程學系
;
Department of Computer Science
In smart grid, smart meters are deployed to collect power consumption data periodically, and the data are analyzed to improve the efficiency of power transmission and distribution. The collected consumption data may leak the usage patterns of domestic appliances, so that it may damage the behavior privacy of customers. Most related work to protect data privacy in smart grid relies on cryptographic primitives, for example, encryption, which induces a large amount of power consumption overhead. In this paper, we make the first attempt to propose solutions without any cryptographic computation to protect user privacy. The privacy in smart grid is formally defined in the paper. Three schemes are proposed: random perturbation scheme (RPS), random walk scheme (RWS), and distance-bounded random walk with perturbation scheme (DBS). Three algorithms are also proposed in each scheme, respectively. All schemes are ultra-lightweight in terms of computation without relying any cryptographic primitive. The privacy, soundness, and accuracy of proposed schemes are guaranteed and justified by strict analysis.
RISE: A RelIable and SEcure Scheme for Wireless Machine to Machine Communications
(2013-02-01)
Ren, Wei
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Yu, Linchen
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Ma, Liangli
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Ren, Yi
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資訊工程學系
Wireless Machine to Machine (M2M) communications enable ubiquitous sensing, controlling, and acting via sensors, actuators, and actors. Reliability and security are of foremost importance in wireless M2M systems. A simple, target distinguishing attack can result in M2M\'s failure. This paper presents a RelIable and SEcure scheme, RISE, which is a package of policies that guarantee the reliability of data (including sensor reports and actuator instructions) and devices (including sensors, actuators, and actors). The data reliability is improved by four algorithms, ChooseMedian, ChooseMost, ChooseNearest, and Trust-based Enhancement. Report attainability is improved via m repeat-sending and n multiple-reporting algorithms. Device reliability is guaranteed by device-indistinguishability, which comprises data-indistinguishability and behavior-indistinguishability. The security requirements are formally defined, and the security analysis proves the soundness and completeness of the scheme.