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Description
In this dissertation, two interrelated problems of service-based systems (SBS) are addressed: protecting users' data confidentiality from service providers, and managing performance of multiple workflows in SBS. Current SBSs pose serious limitations to protecting users' data confidentiality. Since users' sensitive data is sent in unencrypted forms to remote machines owned

In this dissertation, two interrelated problems of service-based systems (SBS) are addressed: protecting users' data confidentiality from service providers, and managing performance of multiple workflows in SBS. Current SBSs pose serious limitations to protecting users' data confidentiality. Since users' sensitive data is sent in unencrypted forms to remote machines owned and operated by third-party service providers, there are risks of unauthorized use of the users' sensitive data by service providers. Although there are many techniques for protecting users' data from outside attackers, currently there is no effective way to protect users' sensitive data from service providers. In this dissertation, an approach is presented to protecting the confidentiality of users' data from service providers, and ensuring that service providers cannot collect users' confidential data while the data is processed or stored in cloud computing systems. The approach has four major features: (1) separation of software service providers and infrastructure service providers, (2) hiding the information of the owners of data, (3) data obfuscation, and (4) software module decomposition and distributed execution. Since the approach to protecting users' data confidentiality includes software module decomposition and distributed execution, it is very important to effectively allocate the resource of servers in SBS to each of the software module to manage the overall performance of workflows in SBS. An approach is presented to resource allocation for SBS to adaptively allocating the system resources of servers to their software modules in runtime in order to satisfy the performance requirements of multiple workflows in SBS. Experimental results show that the dynamic resource allocation approach can substantially increase the throughput of a SBS and the optimal resource allocation can be found in polynomial time
ContributorsAn, Ho Geun (Author) / Yau, Sik-Sang (Thesis advisor) / Huang, Dijiang (Committee member) / Ahn, Gail-Joon (Committee member) / Santanam, Raghu (Committee member) / Arizona State University (Publisher)
Created2012
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Description
Access control has been historically recognized as an effective technique for ensuring that computer systems preserve important security properties. Recently, attribute-based

access control (ABAC) has emerged as a new paradigm to provide access mediation

by leveraging the concept of attributes: observable properties that become relevant under a certain security context and are

Access control has been historically recognized as an effective technique for ensuring that computer systems preserve important security properties. Recently, attribute-based

access control (ABAC) has emerged as a new paradigm to provide access mediation

by leveraging the concept of attributes: observable properties that become relevant under a certain security context and are exhibited by the entities normally involved in the mediation process, namely, end-users and protected resources. Also recently, independently-run organizations from the private and public sectors have recognized the benefits of engaging in multi-disciplinary research collaborations that involve sharing sensitive proprietary resources such as scientific data, networking capabilities and computation time and have recognized ABAC as the paradigm that suits their needs for restricting the way such resources are to be shared with each other. In such a setting, a robust yet flexible access mediation scheme is crucial to guarantee participants are granted access to such resources in a safe and secure manner.

However, no consensus exists either in the literature with respect to a formal model that clearly defines the way the components depicted in ABAC should interact with each other, so that the rigorous study of security properties to be effectively pursued. This dissertation proposes an approach tailored to provide a well-defined and formal definition of ABAC, including a description on how attributes exhibited by different independent organizations are to be leveraged for mediating access to shared resources, by allowing for collaborating parties to engage in federations for the specification, discovery, evaluation and communication of attributes, policies, and access mediation decisions. In addition, a software assurance framework is introduced to support the correct construction of enforcement mechanisms implementing our approach by leveraging validation and verification techniques based on software assertions, namely, design by contract (DBC) and behavioral interface specification languages (BISL). Finally, this dissertation also proposes a distributed trust framework that allows for exchanging recommendations on the perceived reputations of members of our proposed federations, in such a way that the level of trust of previously-unknown participants can be properly assessed for the purposes of access mediation.
ContributorsRubio Medrano, Carlos Ernesto (Author) / Ahn, Gail-Joon (Thesis advisor) / Doupe, Adam (Committee member) / Zhao, Ziming (Committee member) / Santanam, Raghu (Committee member) / Huang, Dijiang (Committee member) / Arizona State University (Publisher)
Created2016
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Description
Wireless communication technologies have been playing an important role in modern society. Due to its inherent mobility property, wireless networks are more vulnerable to passive attacks than traditional wired networks. Anonymity, as an important issue in mobile network environment, serves as the first topic that leads to all the research

Wireless communication technologies have been playing an important role in modern society. Due to its inherent mobility property, wireless networks are more vulnerable to passive attacks than traditional wired networks. Anonymity, as an important issue in mobile network environment, serves as the first topic that leads to all the research work presented in this manuscript. Specifically, anonymity issue in Mobile Ad hoc Networks (MANETs) is discussed with details as the first section of research.



To thoroughly study on this topic, the presented work approaches it from an attacker's perspective. Under a perfect scenario, all the traffic in a targeted MANET exhibits the communication relations to a passive attacker. However, localization errors pose a significant influence on the accuracy of the derived communication patterns. To handle such issue, a new scheme is proposed to generate super nodes, which represent the activities of user groups in the target MANET. This scheme also helps reduce the scale of monitoring work by grouping users based on their behaviors.



The first part of work on anonymity in MANET leads to the thought on its major cause. The link-based communication pattern is a key contributor to the success of the traffic analysis attack. A natural way to circumvent such issue is to use link-less approaches. Information Centric Networking (ICN) is a typical instance of such kind. Its communication pattern is able to overcome the anonymity issue with MANET. However, it also comes with its own shortcomings. One of them is access control enforcement. To tackle this issue, a new naming scheme for contents transmitted in ICN networks is presented. This scheme is based on a new Attribute-Based Encryption (ABE) algorithm. It enforces access control in ICN with minimum requirements on additional network components.



Following the research work on ABE, an important function, delegation, exhibits a potential security issue. In traditional ABE schemes, Ciphertext-Policy ABE (CP-ABE), a user is able to generate a subset of authentic attribute key components for other users using delegation function. This capability is not monitored or controlled by the trusted third party (TTP) in the cryptosystem. A direct threat caused from this issue is that any user may intentionally or unintentionally lower the standards for attribute assignments. Unauthorized users/attackers may be able to obtain their desired attributes through a delegation party instead of directly from the TTP. As the third part of work presented in this manuscript, a three-level delegation restriction architecture is proposed. Furthermore, a delegation restriction scheme following this architecture is also presented. This scheme allows the TTP to have full control on the delegation function of all its direct users.
ContributorsLi, Bing (Author) / Huang, Dijiang (Thesis advisor) / Xue, Guoliang (Committee member) / Ahn, Gail-Joon (Committee member) / Zhang, Yanchao (Committee member) / Arizona State University (Publisher)
Created2016
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Description
The presence of a rich set of embedded sensors on mobile devices has been fuelling various sensing applications regarding the activities of individuals and their surrounding environment, and these ubiquitous sensing-capable mobile devices are pushing the new paradigm of Mobile Crowd Sensing (MCS) from concept to reality. MCS aims to

The presence of a rich set of embedded sensors on mobile devices has been fuelling various sensing applications regarding the activities of individuals and their surrounding environment, and these ubiquitous sensing-capable mobile devices are pushing the new paradigm of Mobile Crowd Sensing (MCS) from concept to reality. MCS aims to outsource sensing data collection to mobile users and it could revolutionize the traditional ways of sensing data collection and processing. In the meantime, cloud computing provides cloud-backed infrastructures for mobile devices to provision their capabilities with network access. With enormous computational and storage resources along with sufficient bandwidth, it functions as the hub to handle the sensing service requests from sensing service consumers and coordinate sensing task assignment among eligible mobile users to reach a desired quality of sensing service. This paper studies the problem of sensing task assignment to mobile device owners with specific spatio-temporal traits to minimize the cost and maximize the utility in MCS while adhering to QoS constraints. Greedy approaches and hybrid solutions combined with bee algorithms are explored to address the problem.

Moreover, the privacy concerns arise with the widespread deployment of MCS from both the data contributors and the sensing service consumers. The uploaded sensing data, especially those tagged with spatio-temporal information, will disclose the personal information of the data contributors. In addition, the sensing service requests can reveal the personal interests of service consumers. To address the privacy issues, this paper constructs a new framework named Privacy-Preserving Mobile Crowd Sensing (PP-MCS) to leverage the sensing capabilities of ubiquitous mobile devices and cloud infrastructures. PP-MCS has a distributed architecture without relying on trusted third parties for privacy-preservation. In PP-MCS, the sensing service consumers can retrieve data without revealing the real data contributors. Besides, the individual sensing records can be compared against the aggregation result while keeping the values of sensing records unknown, and the k-nearest neighbors could be approximately identified without privacy leaks. As such, the privacy of the data contributors and the sensing service consumers can be protected to the greatest extent possible.
ContributorsWang, Zhijie (Thesis advisor) / Xue, Guoliang (Committee member) / Sen, Arunabha (Committee member) / Li, Jing (Committee member) / Arizona State University (Publisher)
Created2016