Exploring The Effects Of Multimedia Content On A Question And Answer System

Online Question and Answer (Q&A) websites have been a part of the Internet for many years, the most well-known being Yahoo! Answers. These websites allow us to ask and answer questions with other Internet users around the world, utilizing one of the Internet\u27s greatest strengths: information sharing. In the past, this sharing was restricted to primarily text-based content, and previous research has been almost solely devoted to these text-based Q&A systems. This research includes topics such as improving text-based question quality, and methods for finding the best text-based answer. Now, new Q&A systems such as Jelly have recently been released that utilize multimedia, including images, audio, or video for questions and/or answers. These new multimedia features were not part of previous text-based research, and the objective of this project is to fill that research void: how does the use of multimedia in a question affect the odds of receiving the correct answer? Our findings will not only affect this previous Q&A research on question quality and forwarding, but also reveal new security and privacy concerns. To perform our research, we created several different types of multimedia questions, spanning many different topics. We then studied how users answered each question, using our custom MultiQuery website to facilitate the experiment. This website is unique to Q&A in that it allows for many different multimedia question types, not simply text. Once the experiment was completed, we analyzed the results and determined if and to what degree multimedia use in a question improves or worsens the quality of answers; both overall and for each specific topic of questions. We found that multimedia did in fact have a beneficial effect, especially with images, showing a higher answer rating and correctness percentage for most multimedia types. We also found many security and privacy risks from integrating multimedia into a Q&A website, including loss of privacy through image sharing and voice recognition, as well as security dangers to Q&A system owners through illegal, malicious, or explicit uploaded multimedia content. Our analysis and discussion will help future multimedia Q&A systems as they seek to implement the most effective forms of multimedia, will aid future research into multimedia question quality and forwarding algorithms, and will provide recommendations for safer Q&A security practices that account for multimedia

The Prom Problem: Fair and Privacy-Enhanced Matchmaking with Identity Linked Wishes

In the Prom Problem (TPP), Alice wishes to attend a school dance with Bob and needs a risk-free, privacy preserving way to find out whether Bob shares that same wish. If not, no one should know that she inquired about it, not even Bob. TPP represents a special class of matchmaking challenges, augmenting the properties of privacy-enhanced matchmaking, further requiring fairness and support for identity linked wishes (ILW) – wishes involving specific identities that are only valid if all involved parties have those same wishes. The Horne-Nair (HN) protocol was proposed as a solution to TPP along with a sample pseudo-code embodiment leveraging an untrusted matchmaker. Neither identities nor pseudo-identities are included in any messages or stored in the matchmaker’s database. Privacy relevant data stay within user control. A security analysis and proof-of-concept implementation validated the approach, fairness was quantified, and a feasibility analysis demonstrated practicality in real-world networks and systems, thereby bounding risk prior to incurring the full costs of development. The SecretMatch™ Prom app leverages one embodiment of the patented HN protocol to achieve privacy-enhanced and fair matchmaking with ILW. The endeavor led to practical lessons learned and recommendations for privacy engineering in an era of rapidly evolving privacy legislation. Next steps include design of SecretMatch™ apps for contexts like voting negotiations in legislative bodies and executive recruiting. The roadmap toward a quantum resistant SecretMatch™ began with design of a Hybrid Post-Quantum Horne-Nair (HPQHN) protocol. Future directions include enhancements to HPQHN, a fully Post Quantum HN protocol, and more

Mobile Network and Cloud Based Privacy-Preserving Data Aggregation and Processing

The emerging technology of mobile devices and cloud computing has brought a new and efficient way for data to be collected, processed and stored by mobile users. With improved specifications of mobile devices and various mobile applications provided by cloud servers, mobile users can enjoy tremendous advantages to manage their daily life through those applications instantaneously, conveniently and productively. However, using such applications may lead to the exposure of user data to unauthorised access when the data is outsourced for processing and storing purposes. Furthermore, such a setting raises the privacy breach and security issue to mobile users. As a result, mobile users would be reluctant to accept those applications without any guarantee on the safety of their data. The recent breakthrough of Fully Homomorphic Encryption (FHE) has brought a new solution for data processing in a secure motion. Several variants and improvements on the existing methods have been developed due to efficiency problems. Experience of such problems has led us to explore two areas of studies, Mobile Sensing Systems (MSS) and Mobile Cloud Computing (MCC). In MSS, the functionality of smartphones has been extended to sense and aggregate surrounding data for processing by an Aggregation Server (AS) that may be operated by a Cloud Service Provider (CSP). On the other hand, MCC allows resource-constraint devices like smartphones to fully leverage services provided by powerful and massive servers of CSPs for data processing. To support the above two application scenarios, this thesis proposes two novel schemes: an Accountable Privacy-preserving Data Aggregation (APDA) scheme and a Lightweight Homomorphic Encryption (LHE) scheme. MSS is a kind of WSNs, which implements a data aggregation approach for saving the battery lifetime of mobile devices. Furthermore, such an approach could improve the security of the outsourced data by mixing the data prior to be transmitted to an AS, so as to prevent the collusion between mobile users and the AS (or its CSP). The exposure of users’ data to other mobile users leads to a privacy breach and existing methods on preserving users’ privacy only provide an integrity check on the aggregated data without being able to identify any misbehaved nodes once the integrity check has failed. Thus, to overcome such problems, our first scheme APDA is proposed to efficiently preserve privacy and support accountability of mobile users during the data aggregation. Furthermore, APDA is designed with three versions to provide balanced solutions in terms of misbehaved node detection and data aggregation efficiency for different application scenarios. In addition, the successfully aggregated data also needs to be accompanied by some summary information based on necessary additive and non-additive functions. To preserve the privacy of mobile users, such summary could be executed by implementing existing privacy-preserving data aggregation techniques. Nevertheless, those techniques have limitations in terms of applicability, efficiency and functionality. Thus, our APDA has been extended to allow maximal value finding to be computed on the ciphertext data so as to preserve user privacy with good efficiency. Furthermore, such a solution could also be developed for other comparative operations like Average, Percentile and Histogram. Three versions of Maximal value finding (Max) are introduced and analysed in order to differentiate their efficiency and capability to determine the maximum value in a privacy-preserving manner. Moreover, the formal security proof and extensive performance evaluation of our proposed schemes demonstrate that APDA and its extended version can achieve stronger security with an optimised efficiency advantage over the state-of-the-art in terms of both computational and communication overheads. In the MCC environment, the new LHE scheme is proposed with a significant difference so as to allow arbitrary functions to be executed on ciphertext data. Such a scheme will enable rich-mobile applications provided by CSPs to be leveraged by resource-constraint devices in a privacy-preserving manner. The scheme works well as long as noise (a random number attached to the plaintext for security reasons) is less than the encryption key, which makes it flexible. The flexibility of the key size enables the scheme to incorporate with any computation functions in order to produce an accurate result. In addition, this scheme encrypts integers rather than individual bits so as to improve the scheme’s efficiency. With a proposed process that allows three or more parties to communicate securely, this scheme is suited to the MCC environment due to its lightweight property and strong security. Furthermore, the efficacy and efficiency of this scheme are thoroughly evaluated and compared with other schemes. The result shows that this scheme can achieve stronger security under a reasonable cost