864 research outputs found
Condensation in hybrid superconducting-cavity–microscopic-spins systems with finite-bandwidth drive
Using Keldysh field theory, we find conditions for nonequilibrium condensation in the open Tavis-Cummings model under a direct finite-bandwidth incoherent cavity drive. Experimentally, we expect the condensation transition to be easily accessible to hybrid superconducting systems coupled to microscopic spins, as well as to many other incoherently driven light-matter systems. In our theoretical analysis, we explicitly incorporate the drive's spectral distribution into the saddle-point description. We show that the injected incoherent photons create a drive-dependent effective coupling between spin-1/2 particles. The condensation transition arises at a critical regime of driving which we can now accurately predict. Our results also provide important guidelines for future quantum simulation experiments of nonequilibrium phases with hybrid devices
Digital habits and use of the internet as source of sexual and reproductive health information among undergraduates in northern Nigeria
Background: Surfing the internet and networking via social media have evolved at a startling pace. Objectives: To determine internet and social media habits and identify predictors of their use as sexual and reproductive health resource among Bayero University students. Study Design: A cross section of 385 students was interviewed using pre-tested anonymous structured self-completed questionnaires. Results: Nearly all students 98.4% (n=377) had accessed the internet and most 96.3% (n=363) had visited social media sites. Face book 57.3% (n=208), Twitter 22.3% (n=81) and Blackberry Messenger 8.8% (n=32) were the most popular among students. Of those with internet access,51.2%,46.2%, 39.2% and 38.5% mainly searched for information on HIV/AIDS, STI, sexual activities and menstrual problems respectively. There was more than two-fold likelihood of accessing online sexual information among female students compared to males, adjusted Odds ratio (aOR=2.52); 95% Confidence Interval (95%CI= 2.41-4.86). Similarly, ever-married students had more than twice the chance relative to single students (aOR=2.2, 95%CI=1.17-4.28). Furthermore, younger students (<20 years) were twice more likely to have used online resources compared to their older colleagues (≥30 years) (aOR=2.12, 95%CI=1.32-4.17). Conclusion: Undergraduate students are increasingly turning to the internet for sexual and reproductive health information. This presents an opportunity for programming.Key words: Internet, Social media, Reproductive, Sexual health, information source
Identity-based remote data integrity checking with perfect data privacy preserving for cloud storage
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Remote data integrity checking (RDIC) enables a
data storage server, such as a cloud server, to prove to a
verifier that it is actually storing a data owner’s data honestly.
To date, a number of RDIC protocols have been proposed in
the literature, but almost all the constructions suffer from the
issue of a complex key management, that is, they rely on the
expensive public key infrastructure (PKI), which might hinder
the deployment of RDIC in practice. In this paper, we propose
a new construction of identity-based (ID-based) RDIC protocol
by making use of key-homomorphic cryptographic primitive
to reduce the system complexity and the cost for establishing
and managing the public key authentication framework in PKI
based RDIC schemes. We formalize ID-based RDIC and its
security model including security against a malicious cloud server
and zero knowledge privacy against a third party verifier. We
then provide a concrete construction of ID-based RDIC scheme
which leaks no information of the stored files to the verifier
during the RDIC process. The new construction is proven secure
against the malicious server in the generic group model and
achieves zero knowledge privacy against a verifier. Extensive
security analysis and implementation results demonstrate that
the proposed new protocol is provably secure and practical in
the real-world applications.This work is supported by
the National Natural Science Foundation of China
(61501333,61300213,61272436,61472083), Fok Ying Tung
Education Foundation (141065), Program for New Century
Excellent Talents in Fujian University (JA1406
An energy efficient interference-aware routing protocol for underwater WSNs
Interference-aware routing protocol design for underwater wireless sensor networks (UWSNs) is one of the key strategies in reducing packet loss in the highly hostile underwater environment. The reduced interference causes efficient utilization of the limited battery power of the sensor nodes that, in consequence, prolongs the entire network lifetime. In this paper, we propose an energy-efficient interference-aware routing (EEIAR) protocol for UWSNs. A sender node selects the best relay node in its neighborhood with the lowest depth and the least number of neighbors. Combination of the two routing metrics ensures that data packets are forwarded along the least interference paths to reach the final destination. The proposed work is unique in that it does not require the full dimensional localization information of sensor nodes and the network total depth is segmented to identify source, relay and neighbor nodes. Simulation results reveal better performance of the scheme than the counterparts DBR and EEDBR techniques in terms of energy efficiency, packet delivery ratio and end-to-end delay
Platform-independent Secure Blockchain-Based Voting System
Cryptographic techniques are employed to ensure the security of voting systems in order to increase its wide adoption. However, in such electronic voting systems, the public bulletin board that is hosted by the third party for publishing and auditing the voting results should be trusted by all participants. Recently a number of blockchain-based solutions have been proposed to address this issue. However, these systems are impractical to use due to the limitations on the voter and candidate numbers supported, and their security framework, which highly depends on the underlying blockchain protocol and suffers from potential attacks (e.g., force-abstention attacks). To deal with two aforementioned issues, we propose a practical platform-independent secure and verifiable voting system that can be deployed on any blockchain that supports an execution of a smart contract. Verifiability is inherently provided by the underlying blockchain platform, whereas cryptographic techniques like Paillier encryption, proof-of-knowledge, and linkable ring signature are employed to provide a framework for system security and user-privacy that are independent from the security and privacy features of the blockchain platform. We analyse the correctness and coercion-resistance of our proposed voting system. We employ Hyperledger Fabric to deploy our voting system and analyse the performance of our deployed scheme numerically
RingCT 2.0: A Compact Accumulator-Based (Linkable Ring Signature) Protocol for Blockchain Cryptocurrency Monero
In this work, we initially study the necessary properties and security requirements of Ring Confidential Transaction (RingCT) protocol deployed in the popular anonymous cryptocurrency Monero. Firstly, we formalize the syntax of RingCT protocol and present several formal security definitions according to its application in Monero. Based on our observations on the underlying (linkable) ring signature and commitment schemes, we then put forward a new efficient RingCT protocol (RingCT 2.0), which is built upon the well-known Pedersen commitment, accumulator with one-way domain and signature of knowledge (which altogether perform the functions of a linkable ring signature). Besides, we show that it satisfies the security requirements if the underlying building blocks are secure in the random oracle model. In comparison with the original RingCT protocol,
our RingCT 2.0 protocol presents a significant space saving, namely, the transaction size is independent of the number of groups of input accounts included in the generalized ring while the original RingCT suffers a linear growth with the number of groups, which would allow each block to process more transactions
99mTc-IgG-Lung Scintigraphy in the Assessment of Pulmonary Involvement in Interstitial Lung Disease and Its Comparison With Pulmonary Function Tests and High-Resolution Computed Tomography: A Preliminary Study
Background: The discrimination of inactive inflammatory processes from the active form of the disease is of great importance in the management of interstitial lung disease (ILD).
Objectives: The aim of this study was to determine the efficacy of 99mTc-IgG scan for the detection of severity of disease compared to high-resolution computed tomography (HRCT) and pulmonary function test (PFT).
Patients and Methods: Eight known cases of ILD including four cases of Mustard gas (MG) intoxication and four patients with ILD of unknown cause were included in this study. A population of six patients without lung disease was considered as the control group. The patients underwent PFT and high-resolution computed tomography scan, followed by 99mTc-IgG scan. They were followed up for one year. 99mTc-IgG scan assessment of IgG uptake was accomplished both qualitatively (subjectively) and semiquantitatively.
Results: All eight ILD patients demonstrated a strong increase in 99mTc-IgG uptake in the lungs, compared to the control patients. The 99mTc-IgG scan scores were higher in the patient group (0.64[95% confidence interval (CI)=0.61-0.69])) than the control group (0.35 (0.35[95% CI=0.28-0.40]), (P 0.05). There were no significant correlations between 99mTc-IgG score and HRCT patterns including ground glass opacity, reticular fibrosis and honeycombing (P value > 0.05).
Conclusion: The present results confirmed that 99mTc-IgG scan could be applied to detect the severity of pulmonary involvement, which was well correlated with HRCT findings. This data also showed that the 99mTc-IgG scan might be used as a complement to HRCT in the functional evaluation of the clinical status in ILD; however, further studies are recommended
Anonymous Single-Sign-On for n designated services with traceability
Anonymous Single-Sign-On authentication schemes have been proposed to allow
users to access a service protected by a verifier without revealing their
identity which has become more important due to the introduction of strong
privacy regulations. In this paper we describe a new approach whereby anonymous
authentication to different verifiers is achieved via authorisation tags and
pseudonyms. The particular innovation of our scheme is authentication can only
occur between a user and its designated verifier for a service, and the
verification cannot be performed by any other verifier. The benefit of this
authentication approach is that it prevents information leakage of a user's
service access information, even if the verifiers for these services collude
which each other. Our scheme also supports a trusted third party who is
authorised to de-anonymise the user and reveal her whole services access
information if required. Furthermore, our scheme is lightweight because it does
not rely on attribute or policy-based signature schemes to enable access to
multiple services. The scheme's security model is given together with a
security proof, an implementation and a performance evaluation.Comment: 3
A Distributed Trust Framework for Privacy-Preserving Machine Learning
When training a machine learning model, it is standard procedure for the
researcher to have full knowledge of both the data and model. However, this
engenders a lack of trust between data owners and data scientists. Data owners
are justifiably reluctant to relinquish control of private information to third
parties. Privacy-preserving techniques distribute computation in order to
ensure that data remains in the control of the owner while learning takes
place. However, architectures distributed amongst multiple agents introduce an
entirely new set of security and trust complications. These include data
poisoning and model theft. This paper outlines a distributed infrastructure
which is used to facilitate peer-to-peer trust between distributed agents;
collaboratively performing a privacy-preserving workflow. Our outlined
prototype sets industry gatekeepers and governance bodies as credential
issuers. Before participating in the distributed learning workflow, malicious
actors must first negotiate valid credentials. We detail a proof of concept
using Hyperledger Aries, Decentralised Identifiers (DIDs) and Verifiable
Credentials (VCs) to establish a distributed trust architecture during a
privacy-preserving machine learning experiment. Specifically, we utilise secure
and authenticated DID communication channels in order to facilitate a federated
learning workflow related to mental health care data.Comment: To be published in the proceedings of the 17th International
Conference on Trust, Privacy and Security in Digital Business - TrustBus202
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