Enabling Privacy-preserving Auctions in Big Data

We study how to enable auctions in the big data context to solve many upcoming data-based decision problems in the near future. We consider the characteristics of the big data including, but not limited to, velocity, volume, variety, and veracity, and we believe any auction mechanism design in the future should take the following factors into consideration: 1) generality (variety); 2) efficiency and scalability (velocity and volume); 3) truthfulness and verifiability (veracity). In this paper, we propose a privacy-preserving construction for auction mechanism design in the big data, which prevents adversaries from learning unnecessary information except those implied in the valid output of the auction. More specifically, we considered one of the most general form of the auction (to deal with the variety), and greatly improved the the efficiency and scalability by approximating the NP-hard problems and avoiding the design based on garbled circuits (to deal with velocity and volume), and finally prevented stakeholders from lying to each other for their own benefit (to deal with the veracity). We achieve these by introducing a novel privacy-preserving winner determination algorithm and a novel payment mechanism. Additionally, we further employ a blind signature scheme as a building block to let bidders verify the authenticity of their payment reported by the auctioneer. The comparison with peer work shows that we improve the asymptotic performance of peer works' overhead from the exponential growth to a linear growth and from linear growth to a logarithmic growth, which greatly improves the scalability

Search Me If You Can: Privacy-preserving Location Query Service

Location-Based Service (LBS) becomes increasingly popular with the dramatic growth of smartphones and social network services (SNS), and its context-rich functionalities attract considerable users. Many LBS providers use users' location information to offer them convenience and useful functions. However, the LBS could greatly breach personal privacy because location itself contains much information. Hence, preserving location privacy while achieving utility from it is still an challenging question now. This paper tackles this non-trivial challenge by designing a suite of novel fine-grained Privacy-preserving Location Query Protocol (PLQP). Our protocol allows different levels of location query on encrypted location information for different users, and it is efficient enough to be applied in mobile platforms.Comment: 9 pages, 1 figure, 2 tables, IEEE INFOCOM 201

Popular Opinion Leader intervention for HIV stigma reduction in health care settings.

This study used the Popular Opinion Leader (POL) model to reduce stigma among service providers. The authors focused on the dissemination of intervention messages from trained POL providers to their peer providers and the change of intervention outcome over time. The sample included 880 service providers from 20 intervention hospitals. The levels of message diffusion, prejudicial attitude toward people living with HIV (PLH), and avoidance intent to serve PLH were self-reported at baseline, 6 months, and 12 months. At 6 months, POL providers showed a significantly higher level of message diffusion and lower levels of prejudicial attitude and avoidance intent than non-POL providers. However, such discrepancies diminished at 12 months. The results support the utility of the POL model in stigma reduction interventions. The observed changes were documented not only in POLs but also in non-POLs after a certain period of time. This finding informed the design and implementation of future stigma reduction efforts and POL intervention programs

Gender Differences in Depressive Symptoms Among HIV-Positive Concordant and Discordant Heterosexual Couples in China.

HIV seropositive individuals and their heterosexual partners/spouses, either seropositive or seronegative, are facing several mental health challenges. The objective of this study was to examine gender differences in depressive symptoms among HIV-positive concordant and HIV-discordant couples. We identified heterosexual couples from participants of a randomized controlled trial conducted in Anhui province, China. A total of 265 couples, comprising 129 HIV+ male/HIV- female couples, 98 HIV- male/HIV+ female couples, and 38 HIV-positive concordant couples, were included in the analyses. We collected data using the computer-assisted personal interview method. We used a linear mixed-effects regression model to assess whether gender differences in depressive symptoms varied across couple types. HIV-positive women reported a significantly higher level of depressive symptoms than their partners/spouses. HIV-positive women with HIV-positive partners had higher depressive symptoms than those with HIV-negative partners, whereas HIV-positive men reported similar levels of depressive symptoms regardless of their partners' serostatus. Among the concordant couples, those with the highest annual family income showed the greatest gender differences in depressive symptoms. We suggest that family interventions should be gender- and couple-type specific and that mental health counseling is warranted not only for HIV-positive women but also for HIV-negative women in an HIV-affected relationship

Antiretroviral Therapy Initiation Following Policy Changes: Observations From China.

China's HIV/AIDS treatment policies have been evolving over the preceding decade. This study describes patterns of antiretroviral therapy (ART) initiation for a sample of people living with HIV/AIDS (PLHIV) in rural Anhui, China, where most PLHIV were infected via paid plasma donation during the 1990s. A total of 481 PLHIV who were receiving ART were included in our analyses. Times between HIV diagnosis and the initiation of ART were examined relative to the time points when major ART-related policies changed in China. More than half (53%) of PLHIV who had been diagnosed by 2003 received ART within 6 months, whereas 93% of PLHIV who had been diagnosed in 2010 or later received ART within 6 months. The study results provide additional support that the "Four Frees and One Care" policy in 2003 and the relaxation of ART eligibility in 2010 have facilitated the initiation of treatment for PLHIV in China

Correlated outcomes of a pilot intervention for people injecting drugs and their family members in Vietnam.

BackgroundThe interrelationship between the well-being of injecting drug users (IDUs) and their family environment has been widely documented. However, few intervention programs have addressed the needs of both IDUs and their family members.MethodsThis study describes a randomized intervention pilot targeting 83 IDUs and 83 of their family members from four communes in Phú Thọ province, Vietnam. The IDUs and family members in the intervention condition received multiple group sessions, with the intent to improve psychological well-being and family relationships. The intervention outcomes (depressive symptoms and family relations) were evaluated at baseline, 3-month and 6-month follow-up assessments.ResultsDepressive symptoms and family relations reported by IDUs were found to be correlated to those reported by their family members. Overall, significant intervention effects on depressive symptoms and family relations were observed for both IDUs and family members. A similar improvement pattern in family relations emerged for both the IDU and family member samples, although the intervention effect of reducing depressive symptoms was more sustainable for family members at the 6-month assessment when compared to the IDU sample.ConclusionThe intervention pilot addressed challenges faced by IDUs and their family members and revealed correlated outcomes for the two groups. Findings suggest a vital need to include family members in future drug prevention and harm reduction intervention efforts

An intervention to improve provider-patient interaction at methadone maintenance treatment in China.

BackgroundThis study evaluated an intervention aiming to improve methadone maintenance therapy (MMT) service providers' interaction with their patients in China.MethodsSixty-eight MMT clinics were randomized to either an intervention or a control condition. Providers in the intervention group attended three group training sessions to enhance their communication skills. Trained providers were encouraged to practice the taught communication skills through provider-initiated individual sessions with their patients. A total of 418 service providers completed assessments from baseline to 24-month. Linear mixed-effects regression models were used to compare self-reported short-term and sustained improvement in provider-patient interaction between the intervention and the control conditions.ResultsThe intervention group service providers perceived significantly greater short-term and sustained improvement in provider-patient interaction compared to the control group service providers (estimated difference (±SE): 1.20 (0.24) and 1.35 (0.33), respectively; p-values < 0.0001). Providers' baseline job satisfaction was significantly associated with a greater perceived improvement in provider-patient interaction for both periods (reg. coef. (±SE): 0.02 (0.01) and 0.04 (0.01) for short-term and sustained periods, respectively; p-values < 0.01).ConclusionStudy findings suggest that the intervention could be beneficial for improving perceived provider-patient interaction in MMT programs. Service providers' job satisfaction should be addressed in training programs for the improvement of provider-patient interaction

Energy-recycling Blockchain with Proof-of-Deep-Learning

An enormous amount of energy is wasted in Proofof-Work (PoW) mechanisms adopted by popular blockchain applications (e.g., PoW-based cryptocurrencies), because miners must conduct a large amount of computation. Owing to this, one serious rising concern is that the energy waste not only dilutes the value of the blockchain but also hinders its further application. In this paper, we propose a novel blockchain design that fully recycles the energy required for facilitating and maintaining it, which is re-invested to the computation of deep learning. We realize this by proposing Proof-of-Deep-Learning (PoDL) such that a valid proof for a new block can be generated if and only if a proper deep learning model is produced. We present a proof-of-concept design of PoDL that is compatible with the majority of the cryptocurrencies that are based on hash-based PoW mechanisms. Our benchmark and simulation results show that the proposed design is feasible for various popular cryptocurrencies such as Bitcoin, Bitcoin Cash, and Litecoin.Comment: 5 page