Location-based services are quickly becoming immensely popular. In addition to services based on users' current location, many potential services rely on users' location history, or their spatial-temporal provenance. Malicious users may lie about their spatial-temporal provenance without a carefully designed security system for users to prove their past locations. In this paper, we present the Spatial-Temporal provenance Assurance with Mutual Proofs (STAMP) scheme. STAMP is designed for ad-hoc mobile users generating location proofs for each other in a distributed setting. However, it can easily accommodate trusted mobile users and wireless access points. STAMP ensures the integrity and non-transferability of the location proofs and protects users' privacy. A semi-trusted Certification Authority is used to distribute cryptographic keys as well as guard users against collusion by a light-weight entropy-based trust evaluation approach. Our prototype implementation on the Android platform shows that STAMP is low-cost in terms of computational and storage resources. Extensive simulation experiments show that our entropy-based trust model is able to achieve high ( > 0.9) collusion detection accuracy.

Many location-based services require a mobile user to continuously prove his location. In absence of a secure mechanism, malicious users may lie about their locations to get these services. Mobility trace, a sequence of past mobility points, provides evidence for the user's locations. In this paper, we propose a Continuous Location Integrity and Provenance (CLIP) Scheme to provide authentication for mobility trace, and protect users' privacy. CLIP uses low-power inertial accelerometer sensor with a light-weight entropy-based commitment mechanism and is able to authenticate the user's mobility trace without any cost of trusted hardware. CLIP maintains the user's privacy, allowing the user to submit a portion of his mobility trace with which the commitment can be also verified. Wireless Access Points (APs) or colocated mobile devices are used to generate the location proofs. We also propose a light-weight spatial-temporal trust model to detect fake location proofs from collusion attacks. The prototype implementation on Android demonstrates that CLIP requires low computational and storage resources. Our extensive simulations show that the spatial-temporal trust model can achieve high (> 0.9) detection accuracy against collusion attacks.

With the ever increasing number of connected devices and the over abundance of data generated by these devices, data privacy has become a critical concern in the Internet of Things (IoT). One promising privacy-preservation approach is Attribute-Based Encryption (ABE), a public key encryption scheme that enables fine-grained access control, scalable key management and flexible data distribution. This paper presents an in-depth performance evaluation of ABE that focuses on execution time, data and network overhead, energy consumption, and CPU and memory usage. We evaluate two major types of ABE, Key-Policy Attribute-Based Encryption (KP-ABE) and Ciphertext-Policy Attribute-Based Encryption (CP-ABE), on different classes of mobile devices including a laptop and a smartphone. To the best of our knowledge, this is the first comprehensive study of ABE dedicated solely to its performance. Our results provide insights into important practical issues of ABE, including what computing resources ABE requires in heterogeneous environments, at what cost ABE offers benefits, and under what situations ABE is best suited for use in the IoT.

With the proliferation of sensor-embedded mobile computing devices, mobile sensing is becoming a popular paradigm to collect information from participating mobile users. Unlike the well-calibrated and well-tested sensor networks, mobile sensing relies on participants with unknown reliability. Data collected from mobile users may be untrustworthy. There are various solutions proposed in the literature for assessing the trustworthiness of the sensing data that describe an individual event or observation. In addition to single-event based trust models, we propose the concept of Provenance Logic, to reason about the logical relations between multiple events by jointly recognizing and linking events from successive sensing observations. We propose an approach that combines logical reasoning and statistical learning techniques. To the best of our knowledge, our work is the first attempt for trust evaluation based on the logical relation among multiple events in the mobile sensing context. We motivate and illustrate our approach with a use case of traffic monitoring mobile sensing. Performance validation has shown that improved trust assessment can be achieved efficiently and effectively on top of single-event based analysis.

Mobile sensing is becoming a popular paradigm to collect information from and outsource tasks to mobile users. These applications deal with lot of personal information, e.g., identity and location. Therefore, we need to pay a deeper attention to privacy and anonymity. However, the knowledge of the data source is desired to evaluate the trustworthiness of the sensing data. Anonymity and trust become two conflicting objectives in mobile sensing. In this paper, we proposeARTSense, a framework to solve the problem of “trust without identity” in mobile sensing. Our solution consists of a privacy-preserving provenance model, a data trust assessment scheme and an anonymous reputation management protocol. In contrast to other recent solutions, our scheme does not require a trusted third party and both positive and negative reputation updates can be enforced. In the trust assessment, we consider contextual factors that dynamically affects the trustworthiness of the sensing data as well as the mutual support and conflict among data from difference sources. Security analysis shows that ARTSense achieves our desired anonymity and security goals. Our prototype implementation on Android demonstrates that ARTSense incurs minimal computation overhead on mobile devices, and simulation results justify that ARTSense captures the trust of information and reputation of participants accurately.

Location-based services are quickly becoming immensely popular. In addition to services based on users' current location, many potential services rely on users' location history, or their spatial-temporal provenance. Malicious users may lie about their spatial-temporal provenance without a carefully designed security system for users to prove their past locations. In this paper, we present the Spatial-Temporal provenance Assurance with Mutual Proofs (STAMP) scheme. In contrast to most existing location proof systems which rely on infrastructure like wireless APs, STAMP is based on co-located mobile devices mutually generating location proofs for each other. This makes STAMP desirable for a wider range of applications. STAMP ensures the integrity and non-transferability of the location proofs and protects users' privacy. We also examine different collusion scenarios and propose a light-weight entropy-based trust evaluation approach to detect fake proofs resulting from collusion attacks. Our prototype implementation on the Android platform shows that STAMP is low-cost in terms of computational and storage resources. Extensive simulation experiments show that our entropy-based trust model is able to achieve high (> 0.9) collusion detection accuracy.

Deployment of public wireless access points (also known as public hotspots) and the prevalence of portable computing devices has made it more convenient for people on travel to access the Internet. On the other hand, it also generates large privacy concerns due to the open environment. However, most users are neglecting the privacy threats because currently there is no way for them to know to what extent their privacy is revealed. In this paper, we examine the privacy leakage in public hotspots from activities such as domain name querying, web browsing, search engine querying and online advertising. We discover that, from these activities multiple categories of user privacy can be leaked, such as identity privacy, location privacy, financial privacy, social privacy and personal privacy. We have collected real data from 20 airport datasets in four countries and discover that the privacy leakage can be up to 68%, which means two thirds of users on travel leak their private information while accessing the Internet at airports. Our results indicate that users are not fully aware of the privacy leakage they can encounter in the wireless environment, especially in public WiFi networks. This fact can urge network service providers and website designers to improve their service by developing better privacy preserving mechanisms.

With the proliferation of sensor-embedded mobile computing devices, participatory sensing is becoming popular to collect information from and outsource tasks to participating users. These applications deal with a lot of personal information, e.g., users' identities and locations at a specific time. Therefore, we need to pay a deeper attention to privacy and anonymity. However, from a data consumer's point of view, we want to know the source of the sensing data, i.e., the identity of the sender, in order to evaluate how much the data can be trusted. “Anonymity” and “trust” are two conflicting objectives in participatory sensing networks, and there are no existing research efforts which investigated the possibility of achieving both of them at the same time. In this paper, we propose ARTSense, a framework to solve the problem of “trust without identity” in participatory sensing networks. Our solution consists of a privacy-preserving provenance model, a data trust assessment scheme and an anonymous reputation management protocol. We have shown that ARTSense achieves the anonymity and security requirements. Validations are done to show that we can capture the trust of information and reputation of participants accurately.

Eclipse and Netbeans are two top of the line Integrated Development Environments (IDEs) for Java development. Both of them provide support for a wide variety of development tasks and have a large user base. This paper provides an analysis and comparison for the compatibility and stability of Eclipse and Netbeans on the three most commonly used operating systems, Windows, Linux and Mac OS. Both IDEs are programmed in Java and use a Bugzilla issue tracker to track reported bugs and feature requests. We looked into the Bugzilla repository databases of these two IDEs, which contains the bug records and histories of these two IDEs. We used some basic data mining techniques to analyze some historical statistics of the bug data. Based on the analysis, we try to answer certain stability-comparison oriented questions in the paper, so that users can have a better idea which of these two IDEs is designed better to work on different platforms.

The quality of information is crucial for decision making in many dynamic information sharing environments such as sensor and tactical networks. Information trustworthiness is an essential parameter in assessing the information quality. In this paper, we present a trust model to evaluate the trustworthiness of information as well as information publishing entities based on information provenance. In our trust model, decision makers can give an evaluation on the information they receive and further adjust the evaluation result to a more accurate value by considering two factors: information similarity and path difference. We introduce Collusion Attacks that may bias the computation and present a mechanism to detect and reduce the effect of Collusion Attacks. Based on the final adjusted information trust, feedback is given to the information publishing nodes to adaptively update their trust scores. Therefore, our collusion-resistant scheme can dynamically assess the trustworthiness of information as well as participating entities in a network and thus effectively enhance the network security. Detailed analysis of the proposed approach is presented along with simulation results.

In this paper, we present a trust model to evaluate the trustworthiness of information as well as the information publishing nodes based on the information provenance. We consider two factors in evaluating the provenance-based information trust: Path Similarity and Information Similarity. In multihop networks, information can flow through multiple hops from multiple paths. We model the similarity between different paths which deliver information about the same event and the similarity between two information items about the same event which are delivered through different paths. Both path and information similarity factors are considered in determining the trust of the information. This information trust is indeed used as a feedback factor to adaptively adjust trust of the nodes in the network. Detailed analysis of the proposed approach is presented along with simulation results for validation.