19 research outputs found
PRO-ORAM: Constant Latency Read-Only Oblivious RAM
Oblivious RAM is a well-known cryptographic primitive to hide data
access patterns. However, the best known ORAM schemes require a logarithmic
computation time in the general case which makes it infeasible for use in real-world applications. In practice, hiding data access patterns should incur a constant
latency per access.
In this work, we present PRO-ORAM --- an ORAM construction that
achieves constant latencies per access in a large class of applications. PRO-ORAM theoretically and empirically
guarantees this for read-only data access
patterns, wherein data is written once followed by read requests.
It makes hiding data access pattern practical
for read-only workloads, incurring sub-second computational latencies
per access for data blocks of 256 KB, over large (gigabyte-sized)
datasets.PRO-ORAM supports throughputs of tens to hundreds of MBps
for fetching blocks, which exceeds network bandwidth available to
average users today. Our experiments suggest that dominant factor in
latency offered by PRO-ORAM is the inherent network throughput of
transferring final blocks, rather than the computational latencies of
the protocol. At its heart, PRO-ORAM utilizes key observations
enabling an aggressively parallelized algorithm of an ORAM construction and
a permutation operation, as well as the use of trusted computing
technique (SGX) that not only provides safety but also offers the
advantage of lowering communication costs
Deterministic, Stash-Free Write-Only ORAM
Write-Only Oblivious RAM (WoORAM) protocols provide privacy by encrypting the
contents of data and also hiding the pattern of write operations over that
data. WoORAMs provide better privacy than plain encryption and better
performance than more general ORAM schemes (which hide both writing and reading
access patterns), and the write-oblivious setting has been applied to important
applications of cloud storage synchronization and encrypted hidden volumes. In
this paper, we introduce an entirely new technique for Write-Only ORAM, called
DetWoORAM. Unlike previous solutions, DetWoORAM uses a deterministic,
sequential writing pattern without the need for any "stashing" of blocks in
local state when writes fail. Our protocol, while conceptually simple, provides
substantial improvement over prior solutions, both asymptotically and
experimentally. In particular, under typical settings the DetWoORAM writes only
2 blocks (sequentially) to backend memory for each block written to the device,
which is optimal. We have implemented our solution using the BUSE (block device
in user-space) module and tested DetWoORAM against both an encryption only
baseline of dm-crypt and prior, randomized WoORAM solutions, measuring only a
3x-14x slowdown compared to an encryption-only baseline and around 6x-19x
speedup compared to prior work
Historical data based energy management in a microgrid with a hybrid energy storage system
In a micro-grid, due to potential reverse output profiles of the Renewable Energy Source (RES) and the load, energy storage devices are employed to achieve high self-consumption of RES and to minimize power surplus flowing back into the main grid. This paper proposes a variable charging/discharging threshold method to manage energy storage system. And an Adaptive Intelligence Technique (AIT) is put forward to raise the power management efficiency. A battery-ultra-capacitor hybrid energy storage system (HESS) with merits of high energy and power density is used to evaluate the proposed method with onsite measured RES output data. Compared with the PSO algorithm based on the precise predicted data of the load and the RES, the results show that the proposed method can achieve better load smoothing and maximum self-consumption of the RES without the requirement of precise load and RES forecasting
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
Consumer-Related Antecedents of Waste Behavior in Online Food Ordering: A Study among Young Adults in China
Food waste in the catering industry currently accounts for almost half of the total food waste in China and entails a large amount of land, water, and labor costs, in addition to the carbon footprint’s impacts on climate change. Under the background of increasing food consumption and waste from online catering, this study investigates the factors influencing the food waste behaviors (FW) of online food ordering in China and provides policy recommendations for food waste reduction. Using survey data from 482 consumers, we constructed a theoretical framework and examined the influence path of each factor using structural equation modeling (SEM) and a bootstrap test. The results showed that young consumers without farming experience and females wasted more on ordering food online. The more frequently the consumer ordered, the more they wasted. The level of consumers’ perceived behavioral control (PBC) was found to be lower than other factors, indicating that it was difficult for consumers to reduce food waste. Attitudes toward behavior (ATT), subjective norm (SN), PBC, and price consciousness (PC) were all positively related to behavioral intention to reduce food waste (BI). PBC and BI were negatively related to FW, and over-consumption behavior (OC) was positively related to FW. BI had a mediating effect on the paths of ATT, PBC, and PC to FW, but the pathway through which PC influenced FW was primarily through BI or PBC, not OC. In our research, BI had no mediating effect between SN and FW. Ultimately, our findings inform some policy recommendations to help nations, restaurants, food-ordering platforms, and consumers reduce waste
Toward Exposing Timing-Based Probing Attacks in Web Applications
Web applications have become the foundation of many types of systems, ranging from cloud services to Internet of Things (IoT) systems. Due to the large amount of sensitive data processed by web applications, user privacy emerges as a major concern in web security. Existing protection mechanisms in modern browsers, e.g., the same origin policy, prevent the users’ browsing information on one website from being directly accessed by another website. However, web applications executed in the same browser share the same runtime environment. Such shared states provide side channels for malicious websites to indirectly figure out the information of other origins. Timing is a classic side channel and the root cause of many recent attacks, which rely on the variations in the time taken by the systems to process different inputs. In this paper, we propose an approach to expose the timing-based probing attacks in web applications. It monitors the browser behaviors and identifies anomalous timing behaviors to detect browser probing attacks. We have prototyped our system in the Google Chrome browser and evaluated the effectiveness of our approach by using known probing techniques. We have applied our approach on a large number of top Alexa sites and reported the suspicious behavior patterns with corresponding analysis results. Our theoretical analysis illustrates that the effectiveness of the timing-based probing attacks is dramatically limited by our approach
Ovarian Stem Cell Nests in Reproduction and Ovarian Aging
The fixed primordial follicles pool theory, which monopolized reproductive medicine for more than one hundred years, has been broken by the discovery, successful isolation and establishment of ovarian stem cells. It has brought more hope than ever of increasing the size of primordial follicle pool, improving ovarian function and delaying ovarian consenescence. Traditional view holds that stem cell aging contributes to the senility of body and organs. However, in the process of ovarian aging, the main factor leading to the decline of the reproductive function is the aging and degradation of ovarian stem cell nests, rather than the senescence of ovarian germ cells themselves. Recent studies have found that the immune system and circulatory system are involved in the formation of ovarian germline stem cell niches, as well as regulating the proliferation and differentiation of ovarian germline stem cells through cellular and hormonal signals. Therefore, we can improve ovarian function and delay ovarian aging by improving the immune system and circulatory system, which will provide an updated program for the treatment of premature ovarian failure (POF) and infertility