278 research outputs found
sHMQV: An Efficient Key Exchange Protocol for Power-limited Devices
In this paper we focus on designing authenticated key exchange protocols for practical scenarios where the party consists of a powerful but untrusted host (e.g., PC, mobile phone, etc) and a power-limited but trusted device (e.g., Trusted Platform Module, Mobile Trusted Module, Smart Card, etc). HMQV and (s,r)OAKE protocols are the state-of-the-art in the integrity of security and efficiency. However, we find that they are not suitable for the above scenarios as all (or part) of the online exponentiation computations must be performed in the power-limited trusted devices, which makes them inefficient for the deployment in practice.
To overcome the above inefficiency, we propose a variant of HMQV protocol, denoted sHMQV, under some new design rationales which bring the following advantages: 1) eliminating the validation of the ephemeral public keys, which costs one exponentiation; 2) the power-limited trusted device only performs one exponentiation, which can be pre-computed offline; 3) all the online exponentiation computations can be performed in the powerful host. The above advantages make sHMQV enjoy better performance than HMQV and (s,r)OAKE, especially when deployed in the scenarios considered in this paper. We finally formally prove the security of sHMQV in the CK model
MicroTEE: Designing TEE OS Based on the Microkernel Architecture
ARM TrustZone technology is widely used to provide Trusted Execution
Environments (TEE) for mobile devices. However, most TEE OSes are implemented
as monolithic kernels. In such designs, device drivers, kernel services and
kernel modules all run in the kernel, which results in large size of the
kernel. It is difficult to guarantee that all components of the kernel have no
security vulnerabilities in the monolithic kernel architecture, such as the
integer overflow vulnerability in Qualcomm QSEE TrustZone and the TZDriver
vulnerability in HUAWEI Hisilicon TEE architecture. This paper presents
MicroTEE, a TEE OS based on the microkernel architecture. In MicroTEE, the
microkernel provides strong isolation for TEE OS's basic services, such as
crypto service and platform key management service. The kernel is only
responsible for providing core services such as address space management,
thread management, and inter-process communication. Other fundamental services,
such as crypto service and platform key management service are implemented as
applications at the user layer. Crypto Services and Key Management are used to
provide Trusted Applications (TAs) with sensitive information encryption, data
signing, and platform attestation functions. Our design avoids the compromise
of the whole TEE OS if only one kernel service is vulnerable. A monitor has
also been added to perform the switch between the secure world and the normal
world. Finally, we implemented a MicroTEE prototype on the Freescale i.MX6Q
Sabre Lite development board and tested its performance. Evaluation results
show that the performance of cryptographic operations in MicroTEE is better
than it in Linux when the size of data is small.Comment: 8 pages, 8 figure
Communication Efficiency Optimization of Federated Learning for Computing and Network Convergence of 6G Networks
Federated learning effectively addresses issues such as data privacy by
collaborating across participating devices to train global models. However,
factors such as network topology and device computing power can affect its
training or communication process in complex network environments. A new
network architecture and paradigm with computing-measurable, perceptible,
distributable, dispatchable, and manageable capabilities, computing and network
convergence (CNC) of 6G networks can effectively support federated learning
training and improve its communication efficiency. By guiding the participating
devices' training in federated learning based on business requirements,
resource load, network conditions, and arithmetic power of devices, CNC can
reach this goal. In this paper, to improve the communication efficiency of
federated learning in complex networks, we study the communication efficiency
optimization of federated learning for computing and network convergence of 6G
networks, methods that gives decisions on its training process for different
network conditions and arithmetic power of participating devices in federated
learning. The experiments address two architectures that exist for devices in
federated learning and arrange devices to participate in training based on
arithmetic power while achieving optimization of communication efficiency in
the process of transferring model parameters. The results show that the method
we proposed can (1) cope well with complex network situations (2) effectively
balance the delay distribution of participating devices for local training (3)
improve the communication efficiency during the transfer of model parameters
(4) improve the resource utilization in the network.Comment: 13 pages, 11 figures, accepted by Frontiers of Information Technology
& Electronic Engineerin
A reusable localized surface plasmon resonance biosensor for quantitative detection of serum squamous cell carcinoma antigen in cervical cancer patients based on silver nanoparticles array
Novobiocin, a Newly Found TRPV1 Inhibitor, Attenuates the Expression of TRPV1 in Rat Intestine and Intestinal Epithelial Cell Line IEC-6
Background and Purpose: Novobiocin (NOVO), an ABC transporter inhibitor, decreases intestinal wall permeability of capsaicin (CAP), an ABC transporter substrate. However, the mechanism of this effect is not consistent with the action of NOVO as an ABC transporter inhibitor. We previously found that CAP can also be transported via TRPV1, which was site-specific in the permeability of CAP across the intestine. We explored the regulation by NOVO of TRPV1 in the present study.Methods: Rats and transfected IEC-6 cells were used as the models to assess intestinal permeability and expression of TRPV1. Ussing chamber and intracellular accumulation were used to evaluate the influence of NOVO on the transport of CAP in vitro. The expression of TRPV1 was detected after administration of NOVO by qRT-PCR, western blot and immunofluorescent imaging. In addition, MTT and lactate dehydrogenase (LDH) were used to evaluate the cytotoxicity of NOVO in both rat and cell models. Finally, the effect of NOVO on the absorption of CAP in vivo was studied by LC-MS/MS.Results:In vitro data showed that there existed a dose-dependent relationship in the range of concentration between 5 and 50 μM, and even 5 μM NOVO could decrease intestinal permeability of CAP across the intestine. Meanwhile, cytosolic accumulation of CAP decreased when NOVO was used simultaneously or 24 h in advance. NOVO exhibited an inhibition level similar to that of ruthenium red (RR) or SB-705498, a TRPV1-specific inhibitor. NOVO down-regulated TRPV1 expression in the intestine and in transfected cells in a concentration-dependent fashion, hinting that its inhibition of the permeability of CAP is due to its inhibition of TRPV1 expression. Immunofluorescent imaging data showed that the fluorescence intensity of TRPV1 was reduced after pre-treatment with NOVO and SB-705498. In vivo data further demonstrated that oral co-administration of NOVO decreased Cmax and AUC of CAP in dosage-dependent ways, consistent with its role as a TRPV1 inhibitor.Conclusion: NOVO could be a potential TRPV1 inhibitor by attenuating the expression of TRPV1 and may be used to attenuate permeability of TRPV1 substrates
Mental health needs of the COVID-19 patients and staff in the Fangcang shelter hospital: a qualitative research in Wuhan, China – ERRATUM
Characteristic Aroma and Molecular Sensory Analysis of Black Teas from Different Regions by Gas Chromatography-Mass Spectrometry and Gas Chromatography-Olfactometry
In order to investigate the differences in the characteristic aroma of black teas from different regions, the volatile aroma compounds of Keemun black tea, Yichang black tea, Dianhong black tea and Yingde black tea were identified by solid phase extraction (SPE) combined with gas chromatography-mass spectrometry (GC-MS) and were evaluated by gas chromatography-olfactory (GC-O). Odor activity value (OAV) calculation and correlation analysis between sensory aroma profile and key aroma-active compounds were performed to analyze the sensory attributes and chemical basis of the characteristic aroma of black tea. The results showed that the four black teas differed in the sensory attributes of seven aroma notes such as floral, sweet and herbal notes. Additionally, 24 differential key aroma compounds were identified (P 1). Geraniol contributed most to black tea aroma with the highest OAV in Keemun black tea (16 581.33), followed by Yichang black tea (7 463.65), Dianhong black tea (2 832.13) and Yingde black tea (467.96). Partial least squares (PLS) regression analysis and Pearson correlation analysis showed that β-ionone, geraniol and indole were responsible for the floral and sweet aroma of Keemun black tea, (Z)-3-hexenol and α-terpineol contributed to the fruity and woody aroma of Dianhong black tea, and 2-heptanol and (Z)-linalooloxide were responsible for the herbal aroma of Yingde black tea. In conclusion, this study has preliminarily clarified the characteristic aroma profiles of black tea from the four regions and their material basis at the molecular level
Observation of Rydberg moir\'e excitons
Rydberg excitons, the solid-state counterparts of Rydberg atoms, have sparked
considerable interest in harnessing their quantum application potentials,
whereas a major challenge is realizing their spatial confinement and
manipulation. Lately, the rise of two-dimensional moir\'e superlattices with
highly tunable periodic potentials provides a possible pathway. Here, we
experimentally demonstrate this capability through the observation of Rydberg
moir\'e excitons (XRM), which are moir\'e trapped Rydberg excitons in monolayer
semiconductor WSe2 adjacent to twisted bilayer graphene. In the strong coupling
regime, the XRM manifest as multiple energy splittings, pronounced redshift,
and narrowed linewidth in the reflectance spectra, highlighting their
charge-transfer character where electron-hole separation is enforced by the
strongly asymmetric interlayer Coulomb interactions. Our findings pave the way
for pursuing novel physics and quantum technology exploitation based on the
excitonic Rydberg states.Comment: 24 pages, including 4 figures and 6 supplementary figure
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