Ideal Tightly Couple (t,m,n) Secret Sharing

As a fundamental cryptographic tool, (t,n)-threshold secret sharing ((t,n)-SS) divides a secret among n shareholders and requires at least t, (t<=n), of them to reconstruct the secret. Ideal (t,n)-SSs are most desirable in security and efficiency among basic (t,n)-SSs. However, an adversary, even without any valid share, may mount Illegal Participant (IP) attack or t/2-Private Channel Cracking (t/2-PCC) attack to obtain the secret in most (t,n)-SSs.To secure ideal (t,n)-SSs against the 2 attacks, 1) the paper introduces the notion of Ideal Tightly cOupled (t,m,n) Secret Sharing (or (t,m,n)-ITOSS ) to thwart IP attack without Verifiable SS; (t,m,n)-ITOSS binds all m, (m>=t), participants into a tightly coupled group and requires all participants to be legal shareholders before recovering the secret. 2) As an example, the paper presents a polynomial-based (t,m,n)-ITOSS scheme, in which the proposed k-round Random Number Selection (RNS) guarantees that adversaries have to crack at least symmetrical private channels among participants before obtaining the secret. Therefore, k-round RNS enhances the robustness of (t,m,n)-ITOSS against t/2-PCC attack to the utmost. 3) The paper finally presents a generalized method of converting an ideal (t,n)-SS into a (t,m,n)-ITOSS, which helps an ideal (t,n)-SS substantially improve the robustness against the above 2 attacks

Establishment of the model system between phytochemicals and gene expression profiles in Macrosclereid cells of Medicago truncatula

Macrosclereid cells, which are a layer in the seed coat of Medicago truncatula, accumulate large amounts of phytochemicals during their development. But little is known about the complex and dynamic changes during macrosclereid cell development. To characterize the phytochemicals and the related gene expression during the development of M. truncatula macrosclereid cells, a high performance liquid chromatography-mass spectrometry (HPLC-MS) assay and microarray study were conducted on transcriptome changes from macrosclereid cell during seed development. A total of 16 flavonoids by HPLC-MS and 4861 genes exhibited significant differences at transcript levels by microarray analysis were identified for macrosclerid cells at six different time points during seed development. 815 abiotic and biotic stress genes, 223 transcriptional factors (TFs), and 155 annotated transporter proteins exhibited differential expression during the development of macrosclereid cells. A total of 102 genes were identified as involved in flavonoid biosynthesis, phenypropanoid biosynthesis, and flavone and flavonol biosynthesis. We performed a weighted gene co-regulatory network (WGCNA) to analyze the gene-flavonoid association and rebuilt the gene regulatory network during macrosclereid cell development. Our studies revealed that macrosclereid cells are, beside as the first barrier of defense against diseases, an excellent model system to investigate the regulatory network that governs flavonoid biosynthesis

An Automated Analyzer for Financial Security of Ethereum Smart Contracts

At present, millions of Ethereum smart contracts are created per year and attract financially motivated attackers. However, existing analyzers do not meet the need to precisely analyze the financial security of large numbers of contracts. In this paper, we propose and implement FASVERIF, an automated analyzer for fine-grained analysis of smart contracts' financial security. On the one hand, FASVERIF automatically generates models to be verified against security properties of smart contracts. On the other hand, our analyzer automatically generates the security properties, which is different from existing formal verifiers for smart contracts. As a result, FASVERIF can automatically process source code of smart contracts, and uses formal methods whenever possible to simultaneously maximize its accuracy. We evaluate FASVERIF on a vulnerabilities dataset by comparing it with other automatic tools. Our evaluation shows that FASVERIF greatly outperforms the representative tools using different technologies, with respect to accuracy and coverage of types of vulnerabilities

Constructing Ideal Secret Sharing Schemes based on Chinese Remainder Theorem

Since $(t,n)$-threshold secret sharing (SS) was initially proposed by Shamir and Blakley separately in 1979, it has been widely used in many aspects. Later on, Asmuth and Bloom presented a $(t,n)$-threshold SS scheme based on the Chinese Remainder Theorem(CRT) for integers in 1983. However, compared with the most popular Shamir\u27s $(t,n)$-threshold SS scheme, existing CRT based schemes have a lower information rate, moreover, they are harder to construct. To overcome these shortcomings of the CRT based scheme, 1) we first propose a generalized $(t,n)$-threshold SS scheme based on the CRT for the polynomial ring over a finite field. We show that our scheme is ideal, i.e., it is perfect in security and has the information rate 1. By comparison, we show that our scheme has a better information rate and is easier to construct compared with existing threshold SS schemes based on the CRT for integers. 2) We show that Shamir\u27s scheme, which is based on the Lagrange interpolation polynomial, is a special case of our scheme. Therefore, we establish the connection among threshold schemes based on the Lagrange interpolation, schemes based on the CRT for integers and our scheme. 3) As a natural extension of our threshold scheme, we present a weighted threshold SS scheme based on the CRT for polynomial rings, which inherits the above advantages of our threshold scheme over existing weighted schemes based on the CRT for integers

STUDY ON ANTI-OSTEOSARCOMA ACTIVITY OF ETHANOL EXTRACT OF VENENUM BUFONIS IN VITRO

Background: Venenum bufonis is the dried white secretion of the auricular and skin glands of Bufo gargarizans Cantor, or Bufo melanostictus Schneider, Bufonidae. It is used in the treatment of deep-rooted carbuncle, boils and swelling; pain in the throat, heart stroke, coma, abdominal pain, vomiting and diarrhea. The objective of this paper is to preliminarily observe the effects of ethanol extract of Venenum bufonis on growth, and proliferation of human osteosarcoma U2OS cell lines, and to provide a theoretical basis for an in-depth study of the clinical application of Venenum bufonis for osteosarcoma inhibition, with its mechanism of action. Materials and Methods: SRB assay was used to determine the effect of Venenum bufonis ethanol extract on U2OS cell line activity, and to detect its inhibitory dose-effect on osteosarcoma cells. FCM was applied to determine the effect of Venenum bufonis ethanol extract on U2OS cell apoptosis and to perform cell cycle analysis. Results: As results, different Venenum bufonis ethanol extracts showed apparent concentration-effect relationships on U2OS cell lines. FCM analysis showed that it had a U2OS apoptosis promoting effect, which increased with increasing concentration. Cell cycle analysis revealed that the Venenum bufonis ethanol extract mainly arrested U2OS in the G0/G1 phase, preventing the cells from progressing to the S phase. Conclusion: The study concluded that Venenum bufonis ethanol extract has an inhibitory effect on proliferation of osteosarcoma U2OS cells

Repurposing dextromethorphan and metformin for treating nicotine-induced cancer by directly targeting CHRNA7 to inhibit JAK2/STAT3/SOX2 signaling

Smoking is one of the most impactful lifestyle-related risk factors in many cancer types including esophageal squamous cell carcinoma (ESCC). As the major component of tobacco and e-cigarettes, nicotine is not only responsible for addiction to smoking but also a carcinogen. Here we report that nicotine enhances ESCC cancer malignancy and tumor-initiating capacity by interacting with cholinergic receptor nicotinic alpha 7 subunit (CHRNA7) and subsequently activating the JAK2/STAT3 signaling pathway. We found that aberrant CHRNA7 expression can serve as an independent prognostic factor for ESCC patients. In multiple ESCC mouse models, dextromethorphan and metformin synergistically repressed nicotine-enhanced cancer-initiating cells (CIC) properties and inhibited ESCC progression. Mechanistically, dextromethorphan non-competitively inhibited nicotine binding to CHRNA7 while metformin downregulated CHRNA7 expression by antagonizing nicotine-induced promoter DNA hypomethylation of CHRNA7. Since dextromethorphan and metformin are two safe FDA-approved drugs with minimal undesirable side-effects, the combination of these drugs has a high potential as either a preventive and/or a therapeutic strategy against nicotine-promoted ESCC and perhaps other nicotine-sensitive cancer types as well