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How to construct secure proxy cryptosystem

Yuan Zhou, Binxing Fang, Zhenfu Cao, Xiaochun Yun, Xiaoming Cheng
2007 Information Sciences  
Proxy cryptosystem, first proposed by Mambo and Okamoto [M.Mambo, E. Okamoto, Proxy cryptosystem: delegation of a power to decrypt ciphertexts, IEICE Trans. Fundam. Electron. Commun. Comput. Sci. E80-A/1 (1997) 54-63], allows the original decryptor to delegate his decrypting capability to the proxies. However, until now, no practical proxy cryptosystem modes are proposed. Therefore, in this paper, we present a novel proxy cryptosystem model: proxy cryptosystem based on time segmentation. Under
more » ... his mode, a security analysis model will be proposed. Furthermore, a proxy cryptosystem scheme is presented as an example. We will show that the proposed scheme is proven security in the proposed security analysis model. Finally, we will give the ID-based version of this construction.
doi:10.1016/j.ins.2007.01.024 fatcat:5sefyqz5e5ajvalyhsg4esszfi

Preparation of Benzyl Quinine-Modified Monolithic Column for Reversed-Phase Capillary Electrochromatography

Xiangju Mao, Xiaofeng Cheng, Zhenfu Lv, Fang Xiao, Lu Liu, Xintao Cheng, Wenshan Ni
2020 Analytical Sciences  
N-Benzylquininium chloride is a versatile functional monomer with quinoline and benzyl groups, which is beneficial for reversed-phase chromatography. In this study, a novel monolithic column with reversed-phase mode was synthesized using N-benzylquininium chloride as the monomer and 3-(acryloyloxy)-2-hydroxypropyl methacrylate as the cross-linker in a binary porogenic solvent consisting of PEG 400 and a 0.05 M sodium hydroxide aqueous solution. The alkaline solution were found to be useful for
more » ... he improvement of the mechanical stability of the porous monoliths. The monolithic column showed excellent reversed-phase selectivity and various compounds, such as alkylbenzenes, phenols and polycyclic aromatic hydrocarbons, were separated successfully. The highest column efficiency was 1.75 × 10 5 N m -1 . The relative standard deviations of the migration time for thiourea and four alkylbenzenes were all less than 5.0%, which indicates the monolithic column has good stability. The application of the monolithic column for the analysis of polycyclic aromatic hydrocarbons in spiked lake water samples illustrated its great potential for practical application.
doi:10.2116/analsci.20p075 pmid:32418933 fatcat:saulggmtcjb3hntog6s75qagce

Effectively Extracting Iceberg Freeboard Using Bi-Temporal Landsat-8 Panchromatic Image Shadows

Zhenfu Guan, Xiao Cheng, Yan Liu, Teng Li, Baogang Zhang, Zhitong Yu
2021 Remote Sensing  
Acknowledgments: We thank the United States Geological Survey (USGS) for providing the Landsat-8 data (, the UAV data created by ZHENFU GUAN have been deposited in  ... 
doi:10.3390/rs13030430 fatcat:k5zzyligizhvreleyc46xqmdqm

Designated server-aided revocable identity-based keyword search on lattice

Ying Guo, Fei Meng, Leixiao Cheng, Xiaolei Dong, Zhenfu Cao
2021 EURASIP Journal on Wireless Communications and Networking  
AbstractPublic key encryption scheme with keyword search is a promising technique supporting search on encrypted data without leaking any information about the keyword. In real applications, it's critical to find an effective revocation method to revoke users in multi-user cryptosystems, when user's secret keys are exposed. In this paper, we propose the first designated server-aided revocable identity-based encryption scheme with keyword search (dSR-IBKS) from lattice. The dSR-IBKS model
more » ... s each user to keep just one private key corresponding with his identity and does not need to communicate with the key generation center or the server during key updating. We have proved that our scheme can achieve chosen keyword indistinguishability in the standard model. In particular, our scheme can designate a unique tester to test and return the search results, therefore no other entity can guess the keyword embedded in the ciphertext by generating search queries and doing the test by itself. We provide a formal security proof of our scheme assuming the hardness of the learning with errors problem on the standard model.
doi:10.1186/s13638-021-02006-1 fatcat:wmypampb25fm3ahf7d7aglsxlq

Compound Technique of Welding and Rolling for Aluminum Alloy Based on Thermal Conductivity Constraint and Local Deformation Strengthening

SONG Gang, CHENG Jiwen, LIU Zhenfu
2020 Journal of Mechanical Engineering  
摘要:铝合金尤其是热处理强化铝合金焊后不可避免会出现热影响区软化现象,导致焊接接头的力学性能显著下降。基 于热导拘束+局部变形强化构想,提出一种铝合金焊轧复合成形方法,系统分析铜垫强制冷却非熔化极惰性气体保护电 弧焊(Tungsten inert gas, TIG)填丝对接焊及焊后轧制复合工艺对 5083-O 和 6061-T6 异种铝合金焊接接头组织和力学性能 的影响。结果表明,采用焊轧复合成形方法,能够得到成形良好且无缺陷的铝合金对接接头,通过轧制使焊接接头同时 发生了纵向变形和横向变形;焊后轧制可以压实铝合金焊缝组织,有效降低焊接接头部分熔化区的宽度,同时热影响区 (包括固溶区和过时效软化区)晶粒发生位向改变甚至转动现象;与自由冷却焊接工艺相比,采用铜垫冷却的焊接接头 6061-T6 侧软化区硬度升高且向焊缝中心产生明显偏移,焊后轧制使两种冷却方式的焊接接头的整体硬度均得到大幅度 提升,其中软化最严重位置硬度值由 59.5 HV 提高到 84.4 HV,提升幅度为 41.8%;两种冷却方式的焊接接头轧制后接 Abstract:The softening of heat
more » ... ted zone (HAZ) inevitably occur after welding of aluminum alloy, especially for heat treatment strengthened aluminum alloy, which leads to the significant decrease of mechanical properties of welded joints. Based on the concept of thermal conductance constrain and local deformation strengthening, a compound technique of welding and rolling for aluminum alloy is proposed, and the effect of the compound technique of tungsten inert gas(TIG) filler wire butt welding with copper pad cooling and rolling on microstructure and mechanical properties of 5083-O and 6061-T6 dissimilar aluminum alloy welded joints is systematically analyzed. The results show that the defect-free and well-formed aluminum alloy butt joints can be obtained by welding-rolling composite forming. The longitudinal and transverse deformations of the welded joints occur simultaneously by rolling. This technique has several advantages over welding alone. These include obvious compaction of weld microstructure, effectively reduction of weld melting zone width, and violent rotation of grain in the heat affected zone (including the solid solution region and the overaging softening region). Compared with the free-cooling welding process, the hardness of the softened zone on the 6061-T6 side of the welded joint with copper pads cooling is increased and the severely softened position is significantly offset to the weld zone. Post-weld rolling greatly increase the overall hardness of the welded joints with two cooling methods. The hardness value at the most severely softened position is increased from 59.5 HV to 84.4 HV, an increase of 41.8%. Compared with free-cooled joints, the tensile strength of the samples by the composite forming with copper pad cooling increases from 197.0 MPa to 288.6 MPa, an increase of 46.5%, which is equivalent to the tensile strength  国家自然科学基金资助项目(U1764251,U1960111)。20200122 收到初稿, 20200228 收到修改稿
doi:10.3901/jme.2020.08.085 fatcat:tcypyipjj5ewlgm2xzyonzjadq

Endoglin promoter hypermethylation identifies a field defect in human primary esophageal cancer

Zhe Jin, Zhenfu Zhao, Yulan Cheng, Ming Dong, Xiaojing Zhang, Liang Wang, Xinmin Fan, Xianling Feng, Yuriko Mori, Stephen J. Meltzer
2013 Cancer  
Endoglin (ENG) is a 180-kDa transmembrane glycoprotein that functions as a component of the transforming growth factor-β receptor complex. Recently, ENG promoter hypermethylation was reported in several human cancers. We examined ENG promoter hypermethylation using real-time quantitative methylation-specific PCR in 260 human esophageal tissues. ENG hypermethylation showed highly discriminative receiver-operator characteristic curve profiles, clearly distinguishing esophageal squamous cell
more » ... oma (ESCC) and esophageal adenocarcinoma (EAC) from normal esophagus (N) (p<0.01). Interestingly, ENG normalized methylation values were significantly higher in ESCC than in N (p<0.01) or EAC (p<0.01). ENG hypermethylation frequency was 46.2% in ESCC and 11.9% in N, but increased early and sequentially during EACassociated neoplastic progression, to 13.3% in Barrett's metaplasia (BE), 25% in dysplastic BE (D), and 26.9% in frank EAC. ENG hypermethylation was significantly higher in N from ESCC patients (mean = 0.0186) than in N from EAC patients (mean = 0.0117; p < 0.05). Treatment of KYSE220 ESCC cells with the demethylating agent, 5-aza-2′-deoxycytidine, reversed ENG methylation and reactivated ENG mRNA expression. We conclude that promoter hypermethylation of ENG is a frequent, tissue-specific event in human ESCC and exhibits a field defect with promising biomarker potential for the early detection of ESCC. In addition, ENG hypermethylation occurs in a subset of human EAC, and early during BE-associated esophageal neoplastic progression.
doi:10.1002/cncr.28276 pmid:23893879 pmcid:PMC3796027 fatcat:cyrp33siebae3o3ftlpa5hvsem

Perfect forward secure identity-based authenticated key agreement protocol in the escrow mode

ShengBao Wang, ZhenFu Cao, ZhaoHui Cheng, Kim-Kwang Raymond Choo
2009 Science in China Series F Information Sciences  
There are several essential features in key agreement protocols such as key escrow (essential when confidentiality, audit trail and legal interception are required) and perfect forward secrecy (i.e., the security of a session key established between two or more entities is guaranteed even when the private keys of the entities are compromised). Majority of the existing escrowable identity-based key agreement protocols, however, only provide partial forward secrecy. Therefore, such protocols are
more » ... nsuitable for real-word applications that require a stronger sense of forward secrecy -perfect forward secrecy. In this paper, we propose an efficient perfect forward secure identity-based key agreement protocol in the escrow mode. We prove the security of our protocol in the random oracle model, assuming the intractability of the Gap Bilinear Diffie-Hellman (GBDH) problem. Security proofs are invaluable tools in assuring protocol implementers about the security properties of protocols. We note, however, that many existing security proofs of previously published identity-based protocols entail lengthy and complicated mathematical proofs. In this paper, our proof adopts a modular approach and, hence, simpler to follow. 1. Prove that a protocol Π has the property of strong partnering. 2. Prove that a related protocol π is secure in a highly reduced security model. 3. The security proof for π in the reduced model is then translated into a security proof for Π in the full model using a Gap assumption [19] . The overall proof technique using the modular approach is far easier than the conventional approach and this forms the second motivation of our paper. Our contributions 1. We propose an efficient ID-based AK protocol (with only a single online pairing computation) that works in the escrow mode. With comparable performance, our new protocol achieves perfect forward secrecy.
doi:10.1007/s11432-009-0135-4 fatcat:wjnjn4ancvfwvmpbdwbtg3cclm

High Efficiency 1.9 kW Single Diode Laser Bar Epitaxially Stacked with a Tunnel Junction

Yuliang Zhao, Zhenfu Wang, Abdullah Demir, Guowen Yang, Shufang Ma, Bingshe Xu, Cheng Sun, Bo Li, Bocang Qiu
2021 IEEE Photonics Journal  
We report on the development of a 940-nm diode laser bar based on epitaxially stacked active regions by employing a tunnel junction structure. The tunnel junction and the device parameters were systematically optimized to achieve high output and power conversion efficiency. A record quasi-continuous wave (QCW) peak power of 1.91 kW at 25°C was demonstrated from a 1-cm wide bar with a 2-mm cavity length at 1 kA drive current (200 μs pulse width and 10 Hz repetition rate). Below the onset of the
more » ... hermal rollover, the slope efficiency was as high as 2.23 W/A. The maximum power conversion efficiency of 61.1% at 25°C was measured at 300 A. Reducing the heatsink temperature to 15°C led to a marginal increase in the peak power to 1.95 kW.
doi:10.1109/jphot.2021.3073732 fatcat:piajppxfirhftmrbzjmjqmgzay

Integrated miRNA profiling and bioinformatics analyses reveal potential causative miRNAs in gastric adenocarcinoma

Xiaojing Zhang, Yin Peng, Zhe Jin, Weiling Huang, Yulan Cheng, Yudan Liu, Xianling Feng, Mengting Yang, Yong Huang, Zhenfu Zhao, Liang Wang, Yanjie Wei (+3 others)
2015 OncoTarget  
Gastric cancer (GC) is one of the leading causes of cancer-related deaths throughout China and worldwide. The discovery of microRNAs (miRNAs) has provided a new opportunity for developing diagnostic biomarkers and effective therapeutic targets in GC. By performing microarray analyses of benign and malignant gastric epithelial cell lines (HFE145, NCI-N87, MKN28, RF1, KATO III and RF48), 16 significantly dysregulated miRNAs were found. 11 of these were validated by real-time qRT-PCR. Based on
more » ... alk online database scans, 703 potential mRNA targets of the 16 miRNAs were identified. Bioinformatic analyses suggested that these dysregulated miRNAs and their predicted targets were principally involved in tumor pathogenesis, MAPK signaling, and apoptosis. Finally, miRNA-gene network analyses identified miRNA-125b as a crucial miRNA in GC development. Taken together, these results develop a comprehensive expression and functional profile of differentially expressed miRNAs related to gastric oncogenesis. This profile may serve as a potential tool for biomarker and therapeutic target identification in GC patients.
doi:10.18632/oncotarget.5419 pmid:26460735 pmcid:PMC4741736 fatcat:wplltt3sezhf3fcwiqz3amyoa4

Temporal evolution in caveolin 1 methylation levels during human esophageal carcinogenesis

Zhe Jin, Liang Wang, Ziyi Cao, Yulan Cheng, Yan Gao, Xianling Feng, Si Chen, Huimin Yu, Wenjing Wu, Zhenfu Zhao, Ming Dong, Xiaojing Zhang (+4 others)
2014 BMC Cancer  
Esophageal cancer ranks eighth among frequent cancers worldwide. Our aim was to investigate whether and at which neoplastic stage promoter hypermethylation of CAV1 is involved in human esophageal carcinogenesis. Methods: Using real-time quantitative methylation-specific PCR (qMSP), we examined CAV1 promoter hypermethylation in 260 human esophageal tissue specimens. Real-time RT-PCR and qMSP were also performed on OE33 esophageal cancer cells before and after treatment with the demethylating
more » ... t, 5-aza-2'-deoxycytidine (5-Aza-dC). Results: CAV1 hypermethylation showed highly discriminative ROC curve profiles, clearly distinguishing esophageal adenocarcinomas (EAC) and esophageal squamous cell carcinomas (ESCC) from normal esophagus (NE) (EAC vs. NE, AUROC = 0.839 and p < 0.0001; ESCC vs. NE, AUROC = 0.920 and p < 0.0001). Both CAV1 methylation frequency and normalized methylation value (NMV) were significantly higher in Barrett's metaplasia (BE), low-grade and high-grade dysplasia occurring in BE (D), EAC, and ESCC than in NE (all p < 0.01, respectively). Meanwhile, among 41 cases with matched NE and EAC or ESCC, CAV1 NMVs in EAC and ESCC (mean = 0.273) were significantly higher than in corresponding NE (mean = 0.146; p < 0.01, Student's paired t-test). Treatment of OE33 EAC cells with 5-Aza-dC reduced CAV1 methylation and increased CAV1 mRNA expression. Conclusions: CAV1 promoter hypermethylation is a frequent event in human esophageal carcinomas and is associated with early neoplastic progression in Barrett's esophagus.
doi:10.1186/1471-2407-14-345 pmid:24885118 pmcid:PMC4035847 fatcat:3vgdhnwgdbc4lkv27xbpnrmore

MAL hypermethylation is a tissue-specific event that correlates with MAL mRNA expression in esophageal carcinoma

Zhe Jin, Liang Wang, Yuan Zhang, Yulan Cheng, Yan Gao, Xianling Feng, Ming Dong, Ziyi Cao, Si Chen, Huimin Yu, Zhenfu Zhao, Xiaojing Zhang (+4 others)
2013 Scientific Reports  
MAL promoter hypermethylation was examined in 260 human esophageal specimens using real-time quantitative methylation-specific PCR (qMSP). MAL hypermethylation showed highly discriminative ROC curve profiles which clearly distinguished esophageal adenocarcinomas (EAC) from both esophageal squamous cell carcinomas (ESCC) and normal esophagus (NE). Both MAL methylation frequency and normalized methylation value (NMV) were significantly higher in Barrett's esophagus (BE), dysplastic BE, and EAC
more » ... n in ESCC or in NE. Among matched NE and EAC samples, MAL NMVs in EAC were significantly higher than in corresponding NE. There was a significant correlation between MAL hypermethylation and BE segment length. Treatment with 5-aza-29-deoxycytidine reversed MAL methylation and reactivated MAL mRNA expression in OE33 EAC cells. MAL mRNA levels in EACs with unmethylated MAL were significantly higher than in EACs with methylated MAL. MAL hypermethylation is a common, tissue-specific event in human EAC and correlates with clinical neoplastic progression risk factors.
doi:10.1038/srep02838 pmid:24088706 pmcid:PMC3789153 fatcat:u6kkihtij5fvpo2gzzcizeleky

Key factors affecting the spatial variation of summer maize yield in Henan Province, China

Zhenfu WU, Yanfeng ZHAO, Daoquan CHENG, Jie CHEN, 1. School of Public Administration, Zhengzhou University, Zhengzhou 450001, China2. School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China3. Station of Soil and Fertilizer Extension Service, Henan Province, Zhengzhou 450002, China
2019 资源科学  
1 引言 作物产量及其空间分异特征是区域农田自然 资源禀赋、 物质技术投入、 作物品种质量以及农艺管 理措施等多种因素共同作用的结果, 系统分析和定 量表达这些因素的影响, 对于开展粮食生产功能区 规划与基本农田划定、 中低产田改良与高标准粮田 建设、 因地制宜选择种植制度与作物品种、 全面实 施 "藏粮于地, 藏粮于技" 战略具有重要参考意义。 作物产量影响因素研究长期以来一直是农学 等相关学科门类的一个热点研究领域。总结和分 析以往的研究案例发现, 绝大多数研究可以归入两 种类型: 一类是集中研究案例地区施肥 [1-4] 、 土壤 [5-6] 、 气候 [7-13] 、 品种 [14-16] 、 灌溉 [17-18] 等某一种因素对作物产 量的影响, 如鲁艳红等 [1] 通过长期定位肥料试验和 盆栽试验结果, 发现氮磷钾肥或氮磷钾肥配施稻草 均能提高双季稻产量; 檀满枝等 [5] 应用模糊 C 均值 算法, 在河南省封丘案例区证明了土壤剖面质地构 型对小麦产量的显著影响; 戴彤等 [13] 分析了气候因 素对中国西南地区 1961-2010 年春玉米产量的影 响,
more » ... 低、 温度升高以及降水减少 等气候因子的变化造成作物减产; Qian 等 [14] 基于中 国 1980-2013 年间玉米产量数据, 利用一系列方法 量化了品种对玉米增产的贡献, 证实了玉米品种更 新在以往 20 多年玉米产量提升过程中的重要作用; Corcoles 等 [18] 在发现案例区甜玉米的产量与品质受 灌溉方案显著影响的基础上, 进一步确定了甜玉米 产量最高、 品质最优的当季度最佳灌溉水量。另一 类则集中分析和研究不同因素在影响作物产量时
doi:10.18402/resci.2019.10.15 fatcat:pfj4nn6z5vbijp4oawim2bw6m4

The recommendations of Chinese Parkinson's disease and movement disorder society consensus on therapeutic management of Parkinson's disease

Shengdi Chen, Piu Chan, Shenggang Sun, Haibo Chen, Baorong Zhang, Weidong Le, Chunfeng Liu, Guoguang Peng, Beisha Tang, Lijuan Wang, Yan Cheng, Ming Shao (+14 others)
2016 Translational Neurodegeneration  
Parkinson's disease (PD) is a chronic, progressive and debilitating disease, which affects over 2.5 million people in China. PD is characterized clinically by resting tremor, muscular rigidity, bradykinesia and postural instability. As the disease progresses, additional complications can arise such as non-motor and neurobehavioral symptoms. Pharmacological treatment and surgical intervention for PD have been implemented in China. Until 10 years ago, there was lack of standardization for the
more » ... gement of PD in different regions and among different physicians, leading to different treatment levels in different regions and different physicians. Since then, the Chinese Parkinson's Disease and Movement Disorder Society have published three versions of guidelines for the management of PD in China, in 2006China, in , 2009China, in and 2014 Correspondingly, the overall level of treatment for PD in China improved. Objectives: To update the treatment guidelines based on current foreign and domestic practice guidelines and clinical evidence, and to improve the treatment options available to physicians in the management of PD. Summary: A variety of treatment recommendations in the treatment guidelines have been proposed, including physical activity and disease-modifying medication, which should be initiated at the early-stage of the disease. The principles of dosage titration should be followed to avoid acute adverse reactions to the drugs, to achieve a satisfactory clinical effect with a low dose and to reduce the incidence of long-term motor complications. Moreover, different treatment strategies should be considered at different stages of the disease. Importantly, treatment guidelines and personalized treatments should be valued equally. A set of treatment recommendations has been developed to assist physicians to improve and optimize clinical outcomes for patients with PD in China.
doi:10.1186/s40035-016-0059-z pmid:27366321 pmcid:PMC4928283 fatcat:gjfw5x556jakfm3trnobsvbdh4

SMG-1 inhibition by miR-192/-215 causes epithelial-mesenchymal transition in gastric carcinogenesis via activation of Wnt signaling

Xiaojing Zhang, Yin Peng, Yong Huang, Mengting Yang, Ruibin Yan, Yanqiu Zhao, Yulan Cheng, Xi Liu, Shiqi Deng, Xianling Feng, Huijuan Lin, Huimin Yu (+11 others)
2017 Cancer Medicine  
SMG-1,a member of the phosphoinositide kinase-like kinase family, functioned as a tumor suppressor gene. However, the role of SMG-1 in GC remain uncharacterized. In this study, regulation of SMG-1 by miR-192 and-215, along with the biological effects of this modulation, were studied in GC. We used gene microarrays to screening and luciferase reporter assays were to verify the potential targets of miR-192 and-215. Tissue microarrays analyses were applied to measure the levels of SMG-1 in GC
more » ... es. Western blot assays were used to assess the signaling pathway of SMG-1 regulated by miR-192 and-215 in GC. SMG-1 was significantly downregulated in GC tissues.The proliferative and invasive properties of GC cells were decreased by inhibition of miR-192 and-215, whereas an SMG-1siRNA rescued the inhibitory effects. Finally, SMG-1 inhibition by miR-192 and-215 primed Wnt signaling and induced EMT. Wnt signaling pathway proteins were decreased markedly by inhibitors of miR-192 and-215, while SMG-1 siRNA reversed the inhibition apparently. Meanwhile, miR-192 and-215 inhitibtors increased E-cadherin expression and decreased Ncadherin and cotransfection of SMG-1 siRNA reversed these effects. In summary, these findings illustrate that SMG-1 is suppressed by miR-192 and-215 and functions as a tumor suppressor in GC by inactivating Wnt signaling and suppressing EMT.
doi:10.1002/cam4.1237 pmid:29239144 pmcid:PMC5773975 fatcat:2jfreubn7vfarfagjk4kdbh6ny

Page 735 of Mathematical Reviews Vol. , Issue 99a [page]

1991 Mathematical Reviews  
, 39019, 39043-39044 Cheng, Sujun . 83049 Cheng, . 90108 Cheng, 20053 Cheng, Yuanji ........ 35084 Cheng, Zheng Qiong 35156 Chentsov, A.  ...  Se Chen, Zhong-wen . 90183 Cheng, Edward Y. c . 68106 Cheng, Juan .......... . 65098 Comme 6 © ......... .... 62091 Chie SC «.:..:..; “See Cheng, Su Chun Cheng, Su Chun ‘ . 62148 Cheng, Sui Sun . 39010  ... 
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