scholarly journals Security-Efficiency Tradeoffs in Searchable Encryption

2019 ◽  
Vol 2019 (4) ◽  
pp. 132-151 ◽  
Author(s):  
Raphael Bost ◽  
Pierre-Alain Fouque
Keyword(s):  
Lower Bounds ◽  
Minimum Cost ◽  
Searchable Encryption ◽  
Search Queries ◽  
Trade Offs ◽  
Encryption Schemes ◽  
Security Properties ◽  
Client State ◽  
The Relationship

Abstract Besides their security, the efficiency of searchable encryption schemes is a major criteria when it comes to their adoption: in order to replace an unencrypted database by a more secure construction, it must scale to the systems which rely on it. Unfortunately, the relationship between the efficiency and the security of searchable encryption has not been widely studied, and the minimum cost of some crucial security properties is still unclear. In this paper, we present new lower bounds on the trade-offs between the size of the client state, the efficiency and the security for searchable encryption schemes. These lower bounds target two kinds of schemes: schemes hiding the repetition of search queries, and forward-private dynamic schemes, for which updates are oblivious. We also show that these lower bounds are tight, by either constructing schemes matching them, or by showing that even a small increase in the amount of leaked information allows for constructing schemes breaking the lower bounds.

Chinese "Cancer Villages"

2020 ◽  
Author(s):  
Ajiang Chen ◽  
Pengli Cheng ◽  
Yajuan Luo
Keyword(s):  
Public Health ◽  
Economic Growth ◽  
Cultural Change ◽  
Social Life ◽  
Social Economic ◽  
Rural China ◽  
Sociological Analysis ◽  
Complex Interactions ◽  
Trade Offs ◽  
The Relationship

The phenomenon of "cancer villages" has emerged in many parts of rural China, drawing media attention and becoming a fact of social life. However, the relationship between pollution and disease is often hard to discern. Through sociological analysis of several villages with different social and economic structures, the authors offer a comprehensive, historically grounded analysis of the coexistence between the incidence of cancer, environmental pollution and villagers’ lifestyles, as well as the perceptions, claims and responses of different actors. They situate the appearance of "cancer villages" in the context of social, economic and cultural change in China, tracing the evolution of the issue over two decades, and providing deep insights into the complex interactions and trade-offs between economic growth, environmental change and public health.

scholarly journals Research on Mediating Mechanisms and the Impact on Food Provision Services in Poor Areas from the Perspective of Stakeholders

2021 ◽  
Vol 18 (19) ◽  
pp. 10510
Author(s):  
Tianwei Geng ◽  
Hai Chen ◽  
Di Liu ◽  
Qinqin Shi ◽  
Hang Zhang
Keyword(s):  
Ecosystem Service ◽  
Behavioral Responses ◽  
The Loess Plateau ◽  
Trade Offs ◽  
Different Types ◽  
Mediating Mechanisms ◽  
The Common ◽  
Food Provision ◽  
The Impact ◽  
The Relationship

Exploring and analyzing the common demands and behavioral responses of different stakeholders is important for revealing the mediating mechanisms of ecosystem service (ES) and realizing the management and sustainable supply of ES. This study took Mizhi County, a poverty-stricken area on the Loess Plateau in China, as an example. First, the main stakeholders, common demands, and behavioral responses in the food provision services were identified. Second, the relationship among stakeholders was analyzed. Finally, this study summarized three types of mediating mechanisms of food provision services and analyzed the influence of the different types of mediating mechanisms. The main conclusions are as follows: (1) Five main stakeholders in the study area were identified: government, farmers, enterprises, cooperatives, and middlemen. (2) Increasing farmers’ income is the common demand of most stakeholders in the study area, and this common demand has different effects on the behavioral responses of different stakeholders. (3) There are three types of mediating mechanisms in the study area: government + farmers mediating corn and mutton, government + enterprises mediating millet, and government + cooperatives mediating apples. On this basis, the effects of the different types of mediating mechanisms on variations in food yield, and trade-offs and synergies in typical townships, were analyzed.

scholarly journals Enumerating Finite Racks, Quandles and Kei

10.37236/3262 ◽  
2013 ◽  
Vol 20 (3) ◽  
Author(s):  
Simon R. Blackburn
Keyword(s):  
Permutation Group ◽  
Lower Bounds ◽  
Binary Operation ◽  
Independent Interest ◽  
Upper And Lower Bounds ◽  
Permutation Groups ◽  
Isomorphism Classes ◽  
Operator Group ◽  
The Relationship

A rack of order $n$ is a binary operation $\vartriangleright$ on a set $X$ of cardinality $n$, such that right multiplication is an automorphism. More precisely, $(X,\vartriangleright)$ is a rack provided that the map $x\mapsto x\vartriangleright y$ is a bijection for all $y\in X$, and $(x\vartriangleright y)\vartriangleright z=(x\vartriangleright z)\vartriangleright (y\vartriangleright z)$ for all $x,y,z\in X$.The paper provides upper and lower bounds of the form $2^{cn^2}$ on the number of isomorphism classes of racks of order $n$. Similar results on the number of isomorphism classes of quandles and kei are obtained. The results of the paper are established by first showing how an arbitrary rack is related to its operator group (the permutation group on $X$ generated by the maps $x\mapsto x\vartriangleright y$ for $y\in Y$), and then applying some of the theory of permutation groups. The relationship between a rack and its operator group extends results of Joyce and of Ryder; this relationship might be of independent interest.

scholarly journals Value-based provider payment: towards a theoretically preferred design

2018 ◽  
Vol 15 (1) ◽  
pp. 94-112 ◽  
Author(s):  
Daniëlle Cattel ◽  
Frank Eijkenaar ◽  
Frederik T. Schut
Keyword(s):  
Health Care ◽  
Pay For Performance ◽  
Empirical Studies ◽  
Risk Profile ◽  
Provider Group ◽  
Payment Incentives ◽  
Trade Offs ◽  
Provider Payment ◽  
Group 2 ◽  
The Relationship

AbstractWorldwide, policymakers and purchasers are exploring innovative provider payment strategies promoting value in health care, known as value-based payments (VBP). What is meant by ‘value’, however, is often unclear and the relationship between value and the payment design is not explicated. This paper aims at: (1) identifying value dimensions that are ideally stimulated by VBP and (2) constructing a framework of a theoretically preferred VBP design. Based on a synthesis of both theoretical and empirical studies on payment incentives, we conclude that VBP should consist of two components: a relatively large base payment that implicitly stimulates value and a relatively small payment that explicitly rewards measurable aspects of value (pay-for-performance). Being the largest component, the base payment design is essential, but often neglected when it comes to VBP reform. We explain that this base payment ideally (1) is paid to a multidisciplinary provider group (2) for a cohesive set of care activities for a predefined population, (3) is fixed, (4) is adjusted for the population’s risk profile and (5) includes risk-mitigating measures. Finally, some important trade-offs in the practical operationalisation of VBP are discussed.

An Attribute-Based Searchable Encryption Scheme for Non-Monotonic Access Structure

2020 ◽  
pp. 263-283 ◽  
Author(s):  
Mamta ­ ◽  
Brij B. Gupta
Keyword(s):  
Access Control ◽  
Searchable Encryption ◽  
Access Structure ◽  
Encryption Scheme ◽  
Security Model ◽  
Secret Key ◽  
Fine Grained ◽  
Diffie Hellman ◽  
Attribute Based Encryption ◽  
Encryption Schemes

Attribute based encryption (ABE) is a widely used technique with tremendous application in cloud computing because it provides fine-grained access control capability. Owing to this property, it is emerging as a popular technique in the area of searchable encryption where the fine-grained access control is used to determine the search capabilities of a user. But, in the searchable encryption schemes developed using ABE it is assumed that the access structure is monotonic which contains AND, OR and threshold gates. Many ABE schemes have been developed for non-monotonic access structure which supports NOT gate, but this is the first attempt to develop a searchable encryption scheme for the same. The proposed scheme results in fast search and generates secret key and search token of constant size and also the ciphertext components are quite fewer than the number of attributes involved. The proposed scheme is proven secure against chosen keyword attack (CKA) in selective security model under Decisional Bilinear Diffie-Hellman (DBDH) assumption.

scholarly journals Analysis of Minimum Cost of Supply Chain Emergencies Based on Diffusion Path Processing

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Yan Cao ◽  
Tian Tian ◽  
Wanyu Wei ◽  
Liang Huang ◽  
Yujia Wu
Keyword(s):  
Supply Chain ◽  
Clustering Algorithm ◽  
Minimum Cost ◽  
Diffusion Path ◽  
Critical Event ◽  
Design Structure ◽  
Perform Cluster Analysis ◽  
The Impact ◽  
The Relationship ◽  
Case Data

In view of the complexity and severity of the impact of supply chain emergencies on enterprise economy, this paper proposes modular processing to improve the design structure matrix (DMS), and the designed clustering algorithm is used to perform cluster analysis of the improved DMS, to predict the possible diffusion path of emergencies, and to establish the critical event diffusion path planning model by designing the critical event diffusion path storage method. As in the case data of a certain type of servo motor of the H Company, after data screening, the diffusion path is classified and stored by analyzing the relationship between each member of the supply chain network. Secondly, the same group of data is put into the method of this paper and other scholars’ to calculate the minimum cost of emergency response in time.

scholarly journals Shift in ecological strategy helps marginal populations of shepherd's purse ( Capsella bursa-pastoris ) to overcome a high genetic load

2020 ◽  
Vol 287 (1927) ◽  
pp. 20200463 ◽  
Author(s):  
Marion Orsucci ◽  
Pascal Milesi ◽  
Johanna Hansen ◽  
Johanna Girodolle ◽  
Sylvain Glémin ◽  
...  
Keyword(s):  
Genetic Load ◽  
Fruit Production ◽  
Ecological Strategy ◽  
Phenotypic Characteristics ◽  
Invasive Ability ◽  
Marginal Populations ◽  
The Core ◽  
Trade Offs ◽  
Natural Range ◽  
The Relationship

The outcome of species range expansion depends on the interplay of demographic, environmental and genetic factors. Self-fertilizing species usually show a higher invasive ability than outcrossers but selfing and bottlenecks during colonization also lead to an increased genetic load. The relationship between genomic and phenotypic characteristics of expanding populations has, hitherto, rarely been tested experimentally. We analysed how accessions of the shepherd's purse, Capsella bursa-pastoris , from the colonization front or from the core of the natural range performed under increasing density of competitors. First, accessions from the front showed a lower fitness than those from the core. Second, for all accessions, competitor density impacted negatively both vegetative growth and fruit production. However, despite their higher genetic load and lower absolute performances, accessions from the front were less affected by competition than accessions from the core. This seems to be due to phenotypic trade-offs and a shift in phenology that allow accessions from the front to avoid competition.

scholarly journals Brain size is correlated with endangerment status in mammals

2016 ◽  
Vol 283 (1825) ◽  
pp. 20152772 ◽  
Author(s):  
Eric S. Abelson
Keyword(s):  
Brain Size ◽  
Extinction Risk ◽  
Small Body ◽  
Cost Benefit ◽  
Metabolic Cost ◽  
Trade Offs ◽  
Extant Species ◽  
Body Sizes ◽  
The Cost ◽  
The Relationship

Increases in relative encephalization (RE), brain size after controlling for body size, comes at a great metabolic cost and is correlated with a host of cognitive traits, from the ability to count objects to higher rates of innovation. Despite many studies examining the implications and trade-offs accompanying increased RE, the relationship between mammalian extinction risk and RE is unknown. I examine whether mammals with larger levels of RE are more or less likely to be at risk of endangerment than less-encephalized species. I find that extant species with large levels of encephalization are at greater risk of endangerment, with this effect being strongest in species with small body sizes. These results suggest that RE could be a valuable asset in estimating extinction vulnerability. Additionally, these findings suggest that the cost–benefit trade-off of RE is different in large-bodied species when compared with small-bodied species.

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