Artificial Internet of Things (AIoT) is that the system collects all kinds of information in real-time through various sensors, and intelligence analysis of the data through machine learning in the ...terminal equipment, edge domains, or cloud centers, including positioning, comparison, forecasting, scheduling, etc. which brings about the data security and privacy issues. The blockchain is a tamper-evident, unforgeable distributed ledger that protects security and privacy through the famous algorithm zk-SNARK, which is also widely used in virtual digital currencies such as Zcash. In addition, by using zk-SNARK technology in the Loopring DEX 3.0 in Ethereum, not only decentralization but also transaction performance can be guaranteed. However, there are three main problems of zk-SNARK, one is the need to guarantee calculation accuracy, two is the long time to generate evidence, especially when using Lagrangian interpolation to QAP the transaction data requires more computation; the last is the poor scalability, especially when nodes need to recalculate all data when adding new transactions. In this paper, we propose a modified zk-SNARK based on Newtonian interpolation, improve the QAP part of zk-SNARK by Newtonian interpolation, and verify the correctness of the scheme through instantiation. Finally, we analyze the computational efficiency of the two interpolation methods, and the results show that Newton interpolation solves the above two problems in the original zk-SNARK, and significantly reduces the time complexity of the algorithm, which can further promote the application of blockchain in data management of AIoT.
Two-party collaborative signature scheme is an important cryptographic technology for user authentication and data integrity protection when using mobile devices for financial and securities ...transactions. However, the two-party collaboration scheme has the following shortcomings: firstly, it is not flexible enough, and it requires the collaborating parties to be secure and trusted; secondly, the two-party collaboration security still needs to be improved. Once a hacker obtains the signature private key and collaborative identity of a mobile device, it can construct a legitimate two-party collaborative signature. Third, the application scenario of two-party co-signature is limited and cannot meet the application scenario of multi-device co-signature. For this reason, this paper designs a multi-party collaborative signature scheme based on SM2 digital signature algorithm in the standard "SM2 Elliptic Curve Public Key Cryptography" of GM/T003-2012. This scheme consists of multiple (more than 2) participants to jointly generate the signature group public key and valid signature in an interactive manner, while ensuring that each user cannot know the signature key other than their own during the signing process. We implement this scheme based on the GMP library. The experimental results show that this scheme is not only flexible but also more secure and trustworthy to meet the application scenario of multi-device collaborative signing. In addition, the time for multiple participants to construct signatures in this scheme is similar, and the time for signature verification is less different from that of the original SM2 signature.
Crowdsourcing refers to a distributed problem-solving mechanism that solves complex problems which are difficult for a single individual to solve by integrating the unknown free and voluntary masses ...on the Internet. In the existing crowdsourcing systems, requesters and workers are usually required to use the crowdsourcing platform as the trust center, and the payment of the fee depends on the third-party central payment institutions. This centralized service mechanism has a large security risk. Once these centers are attacked, or the centers are doing evil, it will bring greater losses to the crowdsourcing parties. Based on the blockchain technology, we propose a new and decentralized trusted service mechanism for crowdsourcing system. The crowdsourcing service process is divided into nine stages, and the smart contract controls the execution of each step in each stage. In addition, the payment is completed by transferring within the blockchain. Finally, we develop smart contracts to conduct experiments based on Ethereum, and conduct comparison experiments. The experimental results show that the effectiveness and applicability of the service of the crowdsourcing system service mechanism without the central institutions.
The SM9 algorithm, established as a national cryptographic standard (GM/T 0044-2016), is an identity-based public key cryptographic technology that includes algorithms for data encryption/decryption, ...key encapsulation, digital signatures, etc. Addressing the issues of private key leakage and centralized signing authority in the national SM9 signature scheme, and avoiding complex key management, this paper proposes a two-party collaborative blind signature scheme based on SM9. The scheme involves the message owner using a blind factor to blind the message for signing, then the two parties with signing authority jointly complete the digital signature on the blinded message. During the signing interaction, neither the plaintext of the message to be signed nor the SM9 signing private key is disclosed, significantly resolving the security issues of the signing private key in SM9 blind signatures. The verification of this co-signature scheme not only ensures the time of verification computation but also guarantees the correctness, universality, and standardization of the signature verification algorithm.
COVID-19 is a major global public health challenge and difficult to control in a short time completely. To prevent the COVID-19 epidemic from continuing to worsen, global scientific research ...institutions have actively carried out studies on COVID-19, thereby effectively improving the prevention, monitoring, tracking, control, and treatment of the epidemic. However, the COVID-19 electronic medical records (CEMRs) among hospitals worldwide are managed independently. With privacy consideration, CEMRs cannot be made public or shared, which is not conducive to in-depth and extensive research on COVID-19 by medical research institutions. In addition, even if new research results are developed, the disclosure and sharing process is slow. To address this issue, we propose a blockchain-based medical research support platform, which can provide efficient and privacy-preserving data sharing against COVID-19. First, hospitals and medical research institutions are treated as nodes on the alliance chain, so consensus and data sharing among the nodes is achieved. Then, COVID-19 patients, doctors, and researchers need to be authenticated in various institutes. Moreover, doctors and researchers need to be registered with the Fabric certificate authority. The CEMRs for COVID-19 patients uses the blockchain's pseudonym mechanism to protect privacy. After that, doctors upload CEMRs on the alliance chain, and researchers can obtain CEMRs from the alliance chain for research. Finally, the research results will be published on the blockchain for doctors to use. The experimental results show that the read and write performance and security performance on the alliance chain meet the requirements, which can promote the wide application of scientific research results against COVID-19.
This paper develops a new mixed frequency macro affine stochastic volatility (MacroSV) model and presents a closed-form formula for pricing VIX futures. In our model, the variance is decomposed into ...long-run and short-run components and the long-run component is driven by the macroeconomic variables. The result from the Monte Carlo experiment shows that the new model outperforms the benchmark model in terms of VIX futures pricing. The results of MacroSV-type models suggest that there is a significant relationship between the volatility and macroeconomic variables. The in-sample forecast results indicate that the models with mixed frequency macroeconomic information outperform the benchmark Heston model. For the out-of-sample pricing, the MacroSV model with the economic information of PPI for the United States has an improvement of 16% over the Heston model.
•We propose a new mixed frequency macro affine stochastic volatility (MacroSV) model.•The new model has a closed-form formula for pricing VIX futures.•The mixed frequency macroeconomic information is valuable for pricing VIX futures.
Pyrethroids may be related to male reproductive system damage. However, the results of many previous studies are contradictory and uncertain. Therefore, a systematic review and a meta-analysis were ...performed to assess the relationship between pyrethroid exposure and male reproductive system damage. A total of 72 articles were identified, among which 57 were selected for meta-analysis, and 15 were selected for qualitative analysis. Pyrethroid exposure affected sperm count (SMD= -2.0424; 95% CI, -2.4699 to -1.6149), sperm motility (SMD=-3.606; 95% CI, -4.5172 to -2.6948), sperm morphology (SMD=2.686; 95% CI, 1.9744 to 3.3976), testis weight (SMD=-1.1591; 95% CI, -1.6145 to -0.7038), epididymal weight (SMD=-1.1576; 95% CI, -1.7455 to -0.5697), and serum testosterone level (SMD=-1.9194; 95% CI, -2.4589 to -1.3798) in the studies of rats. We found that gestational and lactational exposure to pyrethroids can reduce sperm count (SMD=1.8469; 95% CI, -2.9010 to -0.7927), sperm motility (SMD=-2.7151; 95% CI, -3.9574 to -1.4728), testis weight (SMD=-1.4361; 95% CI, -1.8873 to -0.9848), and epididymal weight (SMD=-0.6639; 95% CI, -0.9544 to -0.3733) of F1 offspring. Exposure to pyrethroids can increase malondialdehyde (SMD=3.3451; 95% CI 1.9914 to 4.6988) oxide in testes and can reduce the activities of glutathione (SMD=-2.075; 95% CI -3.0651 to -1.0848), superoxide dismutase (SMD=-2.4856; 95% CI -3.9612 to -1.0100), and catalase (SMD=-2.7564; 95% CI -3.9788 to -1.5340). Pyrethroid exposure and oxidative stress could damage male sperm quality. Gestational and lactational pyrethroid exposure affects the reproductive system of F1 offspring.
Background
The emergence of COVID‐19 pandemic resulted in an urgent need for the development of therapeutic interventions. Of which, neutralizing antibodies play a crucial role in the prevention and ...resolution of viral infection.
Methods
We generated antibody libraries from 18 different COVID‐19 recovered patients and screened neutralizing antibodies to SARS‐CoV‐2 and its mutants. After 3 rounds of panning, 456 positive phage clones were obtained with high affinity to RBD (receptor binding domain). Clones were then reconstituted into whole human IgG for epitope binning assay and all 19 IgG were classified into 6 different epitope groups or Bins.
Results
Although all antibodies were found to bind RBD, the antibodies in Bin2 had superior inhibitory ability of the interaction between spike protein and angiotensin converting enzyme 2 receptor (ACE2). Most importantly, the antibodies from Bin2 showed stronger binding affinity or ability to mutant RBDs (N501Y, W463R, R408I, N354D, V367F, and N354D/D364Y) derived from different SARS‐CoV‐2 strains as well, suggesting the great potential of these antibodies in preventing infection of SARS‐CoV‐2 and its mutations. Furthermore, such neutralizing antibodies strongly restricted the binding of RBD to hACE2 overexpressed 293T cells. Consistently, these antibodies effectively neutralized wildtype and more transmissible mutant pseudovirus entry into hACE2 overexpressed 293T cells. In Vero‐E6 cells, one of these antibodies can even block the entry of live SARS‐CoV‐2 into cells at 12.5 nM.
Conclusions
These results indicate that the neutralizing human antibodies from the patient‐derived antibody libraries have the potential to fight SARS‐CoV‐2 and its mutants in this global pandemic.
The antibody libraries were generated from different COVID‐19 recovered patients for panning neutralizing antibodies to SARS‐CoV‐2 and its mutants. Then the positive clones were sequenced and reconstituted into whole human IgG for epitope binning assay. Finally, the antibodies were demonstrated to have great potential in blocking the infection of SARS‐CoV‐2 and its mutants.
Benzene is harmful to the hematopoietic system and can cause leukemia. However, benzene is still being used in various industries including furniture, rubber, plastic products, and metal product ...manufacturing.
The white blood cell count of workers in general equipment, special equipment, chemical raw materials, and chemical products manufacturing decreased significantly. The enterprises in which benzene concentration exceeded the occupational exposure limit were small enterprises and private enterprises.
Regular health examinations are necessary for benzene-exposed workers. In addition, the monitoring of benzene concentration in small enterprises and private enterprises should be strengthened.
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