Biblio

Cloud-based enterprise search services (e.g., AWS Kendra) have been entrancing big data owners by offering convenient and real-time search solutions to them. However, the problem is that individuals and organizations possessing confidential big data are hesitant to embrace such services due to valid data privacy concerns. In addition, to offer an intelligent search, these services access the user’s search history that further jeopardizes his/her privacy. To overcome the privacy problem, the main idea of this research is to separate the intelligence aspect of the search from its pattern matching aspect. According to this idea, the search intelligence is provided by an on-premises edge tier and the shared cloud tier only serves as an exhaustive pattern matching search utility. We propose Smartness at Edge (SAED mechanism that offers intelligence in the form of semantic and personalized search at the edge tier while maintaining privacy of the search on the cloud tier. At the edge tier, SAED uses a knowledge-based lexical database to expand the query and cover its semantics. SAED personalizes the search via an RNN model that can learn the user’s interest. A word embedding model is used to retrieve documents based on their semantic relevance to the search query. SAED is generic and can be plugged into existing enterprise search systems and enable them to offer intelligent and privacy-preserving search without enforcing any change on them. Evaluation results on two enterprise search systems under real settings and verified by human users demonstrate that SAED can improve the relevancy of the retrieved results by on average ≈24% for plain-text and ≈75% for encrypted generic datasets.

The evolving of context-aware applications are becoming more readily available as a major driver of the growth of future connected smart, autonomous environments. However, with the increasing of security risks in critical shared massive data capabilities and the increasing regulation requirements on privacy, there is a significant need for new paradigms to manage security and privacy compliances. These challenges call for context-aware and fine-grained security policies to be enforced in such dynamic environments in order to achieve efficient real-time authorization between applications and connected devices. We propose in this work a novel solution that aims to provide context-aware security model for Android applications. Specifically, our proposition provides automated context-aware access control model and leverages Attribute-Based Encryption (ABE) to secure data communications. Thorough experiments have been performed and the evaluation results demonstrate that the proposed solution provides an effective lightweight adaptable context-aware encryption model.

In mobile wireless sensor networks (MWSN), data imprecision is a common problem. Decision making in real time applications may be greatly affected by a minor error. Even though there are many existing techniques that take advantage of the spatio-temporal characteristics exhibited in mobile environments, few measure the trustworthiness of sensor data accuracy. We propose a unique online context-aware data cleaning method that measures trustworthiness by employing an initial candidate reduction through the analysis of trust parameters used in financial markets theory. Sensors with similar trajectory behaviors are assigned trust scores estimated through the calculation of “betas” for finding the most accurate data to trust. Instead of devoting all the trust into a single candidate sensor's data to perform the cleaning, a Diversified Trust Portfolio (DTP) is generated based on the selected set of spatially autocorrelated candidate sensors. Our results show that samples cleaned by the proposed method exhibit lower percent error when compared to two well-known and effective data cleaning algorithms in tested outdoor and indoor scenarios.

Digital Signage (DS) is one of the popular IoT technologies deployed in the urban space. DS can provide wayfinding and urban information to city dwellers and convey targeted messaging and advertising to people approaching the DS. With the rise of the online-to-offline (O2O) mobile commerce, DS also become an important marketing tool in urban retailing. However, most digital signage systems today lack interactive feature and context-aware recommendation engine. Few interactive digital signage systems available today are also insufficient in engaging anonymous viewers and also not considering temporal interaction between viewer and DS system. To overcome the above challenges, this paper proposes a context-aware recommender system framework with novel temporal interaction scheme for IoT based interactive digital signage deployed in urban space to engage anonymous viewer. The results of experiments indicate that the proposed framework improves the advertising effectiveness for DS system deployed in public in urban space.

Mobile devices, such as smarthphones, became a common tool in our daily routine. Mobile Applications (a.k.a. apps) are demanding access to contextual information increasingly. For instance, apps require user's environment data as well as their profiles in order to adapt themselves (interfaces, services, content) according to this context data. Mobile apps with this behavior are known as context-aware applications (CAS). Several software infrastructures have been created to help the development of CAS. However, most of them do not store the contextual data, once mobile devices are resource constrained. They are not built taking into account the privacy of contextual data either, due the fact that apps may expose contextual data, without user consent. This paper addresses these topics by extending an existing middleware platform that help the development of mobile context-aware applications. Our extension aims at store and process the contextual data generated from several mobile devices, using the computational power of the cloud, and the definition of privacy policies, which avoid dissemination of unauthorized contextual data.

The exploitation of the opportunistic infrastructure via Device-to-Device (D2D) communication is a critical component towards the adoption of new paradigms such as edge and fog computing. While a lot of work has demonstrated the great potential of D2D communication, it is still unclear whether the benefits of the D2D approach can really be leveraged in practice. In this paper, we develop a software sensor, namely Detector, which senses the infrastructure in proximity of a mobile user. We analyze and evaluate D2D on the wild, i.e., not in simulations. We found that in a realistic environment, a mobile is always co-located in proximity to at least one other mobile device throughout the day. This suggests that a device can schedule tasks processing in coordination with other devices, potentially more powerful, instead of handling the processing of the tasks by itself.