scholarly journals Password-authenticated searchable encryption

2020 ◽  
Author(s):  
Liqun Chen ◽  
Kaibin Huang ◽  
Mark Manulis ◽  
Venkkatesh Sekar
Keyword(s):  
Web Application ◽  
High Performance ◽  
Keyword Search ◽  
Searchable Encryption ◽  
Security Requirements ◽  
Single Server ◽  
Direct Construction ◽  
High Entropy ◽  
Legitimate User ◽  
Diffie Hellman

AbstractWe introduce Password Authenticated Searchable Encryption (PASE), a novel searchable encryption scheme where a single human-memorizable password can be used to outsource (encrypted) data with associated keywords to a group of servers and later retrieve this data through the encrypted keyword search procedure. PASE ensures that only the legitimate user who knows the initially registered password can perform these operations. In particular, PASE guarantees that no single server can mount an offline attack on the user’s password or learn any information about the encrypted keywords. The concept behind PASE protocols extends previous concepts behind searchable encryption by removing the requirement on the client to store high-entropy keys, thus making the protocol device-agnostic on the user side. In this paper, we model the functionality of PASE along with two security requirements (indistinguishability against chosen keyword attacks and authentication) and propose an efficient direct construction in a two-server setting those security we prove in the standard model under the Decisional Diffie–Hellman assumption. Our constructions support outsourcing and retrieval procedures based on multiple keywords and allow users to change their passwords without any need for the re-encryption of the outsourced data. Our theoretical efficiency comparisons and experimental performance and scalability measurements show that the proposed scheme is practical and offers high performance in relation to computations and communications on the user side. The practicality of our PASE scheme is further demonstrated through its implementation within a JavaScript-based web application that can readily be executed on any (mobile) browser and remains practical for commodity user devices such as laptops and smartphones.

Porous spinel-type (Al0.2CoCrFeMnNi)0.58O4-δ high-entropy oxide as a novel high-performance anode material for lithium-ion batteries

2021 ◽  
Vol 56 (13) ◽  
pp. 8127-8142
Author(s):  
Hou-Zheng Xiang ◽  
Hong-Xiang Xie ◽  
Yu-Xue Chen ◽  
Hui Zhang ◽  
Aiqin Mao ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Anode Material ◽  
High Performance ◽  
Lithium Ion ◽  
Spinel Type ◽  
High Entropy

scholarly journals Ciphertext-policy attribute-based encryption with hidden sensitive policy from keyword search techniques in smart city

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Fei Meng ◽  
Leixiao Cheng ◽  
Mingqiang Wang
Keyword(s):  
Smart City ◽  
Keyword Search ◽  
Sensitive Information ◽  
Security Model ◽  
Computational Overhead ◽  
Diffie Hellman ◽  
Attribute Based Encryption ◽  
Iot Devices ◽  
Ciphertext Policy ◽  
Access Policies

AbstractCountless data generated in Smart city may contain private and sensitive information and should be protected from unauthorized users. The data can be encrypted by Attribute-based encryption (CP-ABE), which allows encrypter to specify access policies in the ciphertext. But, traditional CP-ABE schemes are limited because of two shortages: the access policy is public i.e., privacy exposed; the decryption time is linear with the complexity of policy, i.e., huge computational overheads. In this work, we introduce a novel method to protect the privacy of CP-ABE scheme by keyword search (KS) techniques. In detail, we define a new security model called chosen sensitive policy security: two access policies embedded in the ciphertext, one is public and the other is sensitive and hidden. If user's attributes don't satisfy the public policy, he/she cannot get any information (attribute name and its values) of the hidden one. Previous CP-ABE schemes with hidden policy only work on the “AND-gate” access structure or their ciphertext size or decryption time maybe super-polynomial. Our scheme is more expressive and compact. Since, IoT devices spread all over the smart city, so the computational overhead of encryption and decryption can be shifted to third parties. Therefore, our scheme is more applicable to resource-constrained users. We prove our scheme to be selective secure under the decisional bilinear Diffie-Hellman (DBDH) assumption.

scholarly journals Coherent Precipitation and Strengthening in Compositionally Complex Alloys: A Review

Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 878 ◽  
Author(s):  
Qing Wang ◽  
Zhen Li ◽  
Shujie Pang ◽  
Xiaona Li ◽  
Chuang Dong ◽  
...  
Keyword(s):  
Solid Solution ◽  
High Performance ◽  
Particle Morphology ◽  
Precipitation Strengthening ◽  
Second Phase ◽  
High Entropy ◽  
Second Phase Particles ◽  
Alloy Strength ◽  
Solid Solution Matrix ◽  
The Relationship

High-performance conventional engineering materials (including Al alloys, Mg alloys, Cu alloys, stainless steels, Ni superalloys, etc.) and newly-developed high entropy alloys are all compositionally-complex alloys (CCAs). In these CCA systems, the second-phase particles are generally precipitated in their solid-solution matrix, in which the precipitates are diverse and can result in different strengthening effects. The present work aims at generalizing the precipitation behavior and precipitation strengthening in CCAs comprehensively. First of all, the morphology evolution of second-phase particles and precipitation strengthening mechanisms are introduced. Then, the precipitation behaviors in diverse CCA systems are illustrated, especially the coherent precipitation. The relationship between the particle morphology and strengthening effectiveness is discussed. It is addressed that the challenge in the future is to design the stable coherent microstructure in different solid-solution matrices, which will be the most effective approach for the enhancement of alloy strength.

scholarly journals Security Enhanced Anonymous Multiserver Authenticated Key Agreement Scheme Using Smart Cards and Biometrics

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Younsung Choi ◽  
Junghyun Nam ◽  
Donghoon Lee ◽  
Jiye Kim ◽  
Jaewook Jung ◽  
...  
Keyword(s):  
Key Agreement ◽  
User Authentication ◽  
Mutual Authentication ◽  
Smart Cards ◽  
Security Requirements ◽  
Impersonation Attack ◽  
Single Server ◽  
Authenticated Key Agreement ◽  
Session Key ◽  
Authentication Schemes

An anonymous user authentication scheme allows a user, who wants to access a remote application server, to achieve mutual authentication and session key establishment with the server in an anonymous manner. To enhance the security of such authentication schemes, recent researches combined user’s biometrics with a password. However, these authentication schemes are designed for single server environment. So when a user wants to access different application servers, the user has to register many times. To solve this problem, Chuang and Chen proposed an anonymous multiserver authenticated key agreement scheme using smart cards together with passwords and biometrics. Chuang and Chen claimed that their scheme not only supports multiple servers but also achieves various security requirements. However, we show that this scheme is vulnerable to a masquerade attack, a smart card attack, a user impersonation attack, and a DoS attack and does not achieve perfect forward secrecy. We also propose a security enhanced anonymous multiserver authenticated key agreement scheme which addresses all the weaknesses identified in Chuang and Chen’s scheme.

scholarly journals R-OO-KASE: Revocable Online/Offline Key Aggregate Searchable Encryption

2020 ◽  
Vol 5 (4) ◽  
pp. 391-418
Author(s):  
Mukti Padhya ◽  
Devesh C. Jinwala
Keyword(s):  
Radio Frequency Identification ◽  
Keyword Search ◽  
Electrical Power ◽  
Computational Cost ◽  
Security Analysis ◽  
Searchable Encryption ◽  
Resource Constrained ◽  
Encryption Decryption ◽  
Resource Constrained Devices ◽  
Constrained Devices

Abstract The existing Key Aggregate Searchable Encryption (KASE) schemes allow searches on the encrypted dataset using a single query trapdoor, with a feature to delegate the search rights of multiple files using a constant size key. However, the operations required to generate the ciphertext and decrypt it in these schemes incur higher computational costs, due to the computationally expensive pairing operations in encryption/decryption. This makes the use of such schemes in resource-constrained devices, such as Radio Frequency Identification Devices, Wireless Sensor Network nodes, Internet of Things nodes, infeasible. Motivated with the goal to reduce the computational cost, in this paper, we propose a Revocable Online/Offline KASE (R-OO-KASE) scheme, based on the idea of splitting the encryption/decryption operations into two distinct phases: online and offline. The offline phase computes the majority of costly operations when the device is on an electrical power source. The online phase generates final output with the minimal computational cost when the message (or ciphertext) and keywords become known. In addition, the proposed scheme R-OO-KASE also offers multi-keyword search capability and allows the data owners to revoke the delegated rights at any point in time, the two features are not supported in the existing schemes. The security analysis and empirical evaluations show that the proposed scheme is efficient to use in resource-constrained devices and provably secure as compared to the existing KASE schemes.

Signature-Encryption Scheme: A Novel Solution to Mobile Computation

2012 ◽  
Vol 546-547 ◽  
pp. 1415-1420
Author(s):  
Hai Yong Bao ◽  
Man De Xie ◽  
Zhen Fu Cao ◽  
Shan Shan Hong
Keyword(s):  
Mobile Communication ◽  
High Efficiency ◽  
Discrete Logarithm ◽  
Communication Technologies ◽  
Random Oracle ◽  
Security Requirements ◽  
Encryption Scheme ◽  
Daily Lives ◽  
Storage Devices ◽  
Diffie Hellman

Mobile communication technologies have been widely utilized in daily lives, many low-computing-power and weakly-structured-storage devices have emerged, such as PDA, cell phones and smart cards, etc. How to solve the security problems in such devices has become a key problem in secure mobile communication. In this paper, we would like to propose an efficient signature-encryption scheme. The security of the signature part is not loosely related to Discrete Logarithm Problem (DLP) assumption as most of the traditional schemes but tightly related to the Decisional Diffie-Hellman Problem (DDHP) assumption in the Random Oracle Models. Different from the existing solutions, our scheme introduces a trusted agent of the receiver who can filter the “rubbish” messages beforehand. Thus, with high efficiency in computation and storage, it is particularly suitable for the above mobile devices with severely constrained resources and can satisfy the security requirements of mobile computations.

Rapid 3D geological modeling to assess and visualize uncertainties in a web application

2021 ◽  
Author(s):  
Daniel Pflieger ◽  
Miguel de la Varga Hormazabal ◽  
Simon Virgo ◽  
Jan von Harten ◽  
Florian Wellmann
Keyword(s):  
Web Application ◽  
High Performance ◽  
Three Dimensional ◽  
Cloud Services ◽  
Management Approach ◽  
Geological Modeling ◽  
Web Browser ◽  
3D Geological Modeling ◽  
State Management ◽  
Wide Range

<p>Three dimensional modeling is a rapidly developing field in geological scientific and commercial applications. The combination of modeling and uncertainty analysis aides in understanding and quantitatively assessing complex subsurface structures. In recent years, many methods have been developed to facilitate this combined analysis, usually either through an extension of existing desktop applications or by making use of Jupyter notebooks as frontends. We evaluate here if modern web browser technology, linked to high-performance cloud services, can also be used for these types of analyses.</p><p>For this purpose, we developed a web application as proof-of-concept with the aim to visualize three dimensional geological models provided by a server. The implementation enables the modification of input parameters with assigned probability distributions. This step enables the generation of randomized realizations of models and the quantification and visualization of propagated uncertainties. The software is implemented using HTML Web Components on the client side and a Python server, providing a RESTful API to the open source geological modeling tool “GemPy”. Encapsulating the main components in custom elements, in combination with a minimalistic state management approach and a template parser, allows for high modularity. This enables rapid extendibility of the functionality of the components depending on the user’s needs and an easy integration into existing web platforms.</p><p>Our implementation shows that it is possible to extend and simplify modeling processes by creating an expandable web-based platform for probabilistic modeling, with the aim to increase the usability and to facilitate access to this functionality for a wide range of scientific analyses. The ability to compute models rapidly and with any given device in a web browser makes it flexible to use, and more accessible to a broader range of users.</p>

An online service for analysing ozone trends within EOSC-synergy

2021 ◽  
Author(s):  
Tobias Kerzenmacher ◽  
Valentin Kozlov ◽  
Borja Sanchis ◽  
Ugur Cayoglu ◽  
Marcus Hardt ◽  
...  
Keyword(s):  
Data Reduction ◽  
Web Application ◽  
High Performance ◽  
Climate Models ◽  
Open Science ◽  
Primary Data ◽  
Ozone Trends ◽  
User Space ◽  
Rest Api ◽  
Potential Use

<p>The European Open Science Cloud-Synergy (EOSC-Synergy) project delivers services that serve to expand the use of EOSC. One of these services, O3as, is being developed for scientists using chemistry-climate models to determine time series and eventually ozone trends for potential use in the quadrennial Global Assessment of Ozone Depletion, which will be published in 2022. A unified approach from a service like ours, which analyses results from a large number of different climate models, helps to harmonise the calculation of ozone trends efficiently and consistently. With O3as, publication-quality figures can be reproduced quickly and in a coherent way. This is done via a web application where users configure their queries to perform simple analyses. These queries are passed to the O3as service via an O3as REST API call. There, the O3as service processes the query and accesses the reduced dataset. To create a reduced dataset, regular tasks are executed on a high performance computer (HPC) to copy the primary data and perform data preparation (e.g. data reduction, standardisation and parameter unification). O3as uses EGI check-in (OIDC) to identify users and grant access to certain functionalities of the service, udocker (a tool to run Docker containers in multi-user space without root privileges) to perform data reduction in the HPC environment, and the Universitat Politècnica de València (UPV)  Infrastructure Manager to provision service resources (Kubernetes).</p>

Multi-Keyword Searchable Encryption for E-Health System With Multiple Data Writers and Readers

2022 ◽  
pp. 107-131
Author(s):  
Dhruti P. Sharma ◽  
Devesh C. Jinwala
Keyword(s):  
Health System ◽  
Keyword Search ◽  
Medical Data ◽  
Searchable Encryption ◽  
Multiple Stakeholders ◽  
Computational Overhead ◽  
Multiple Data ◽  
Data Owner ◽  
Share Data ◽  
Conjunctive Search

E-health is a cloud-based system to store and share medical data with the stakeholders. From a security perspective, the stored data are in encrypted form that could further be searched by the stakeholders through searchable encryption (SE). Practically, an e-health system with support of multiple stakeholders (that may work as either data owner [writer] or user [reader]) along with the provision of multi-keyword search is desirable. However, the existing SE schemes either support multi-keyword search in multi-reader setting or offer multi-writer, multi-reader mechanism along with single-keyword search only. This chapter proposes a multi-keyword SE for an e-health system in multi-writer multi-reader setting. With this scheme, any registered writer could share data with any registered reader with optimal storage-computational overhead on writer. The proposed scheme offers conjunctive search with optimal search complexity at server. It also ensures security to medical records and privacy of keywords. The theoretical and empirical analysis demonstrates the effectiveness of the proposed work.

scholarly journals Noncovalent π-stacked robust topological organic framework

2020 ◽  
Vol 117 (34) ◽  
pp. 20397-20403
Author(s):  
Dong Meng ◽  
Jonathan Lee Yang ◽  
Chengyi Xiao ◽  
Rui Wang ◽  
Xiaofei Xing ◽  
...  
Keyword(s):  
Porous Structure ◽  
Organic Semiconductors ◽  
Organic Electronics ◽  
High Performance ◽  
Three Dimensional ◽  
Self Healing ◽  
Direct Construction ◽  
Covalent Bonds ◽  
Practical Applications ◽  
Organic Framework

Organic frameworks (OFs) offer a novel strategy for assembling organic semiconductors into robust networks that facilitate transport, especially the covalent organic frameworks (COFs). However, poor electrical conductivity through covalent bonds and insolubility of COFs limit their practical applications in organic electronics. It is known that the two-dimensional intralayer π∙∙∙π transfer dominates transport in organic semiconductors. However, because of extremely labile inherent features of noncovalent π∙∙∙π interaction, direct construction of robust frameworks via noncovalent π∙∙∙π interaction is a difficult task. Toward this goal, we report a robust noncovalent π∙∙∙π interaction-stacked organic framework, namely πOF, consisting of a permanent three-dimensional porous structure that is held together by pure intralayer noncovalent π∙∙∙π interactions. The elaborate porous structure, with a 1.69-nm supramaximal micropore, is composed of fully conjugated rigid aromatic tetragonal-disphenoid-shaped molecules with four identical platforms. πOF shows excellent thermostability and high recyclability and exhibits self-healing properties by which the parent porosity is recovered upon solvent annealing at room temperature. Taking advantage of the long-range π∙∙∙π interaction, we demonstrate remarkable transport properties of πOF in an organic-field-effect transistor, and the mobility displays relative superiority over the traditional COFs. These promising results position πOF in a direction toward porous and yet conductive materials for high-performance organic electronics.

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