• Title/Summary/Keyword: Group Key

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An Group-based Security Protocol for Machine Type Communications in LTE-Advanced (LTE-Advanced에서의 Machine Type Communications을 위한 그룹 기반 보안 프로토콜)

  • Choi, Dae-Sung;Choi, Hyoung-Kee
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.23 no.5
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    • pp.885-896
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    • 2013
  • MTC(Machine Type Communications), providing a variety of services anytime and anywhere by connecting the cellular network to the machine and things without human intervention, is being considered as a major challenge of the next-generation communications. Currently, When a massive MTC devices simultaneously connect to the network, each MTC device needs an independent access authentication process. Because of this process, authentication signaling congestion and overload problems will cause in LTE-Advanced. In this paper, we propose a group-based authentication protocol and a key management protocol. For managing the MTC devices as group units, the proposed protocol elects a group leader and authentications only once with the core network. After the authentication is completed, a group leader manages the rest members and MME(Mobility Management Entity) by constructing a binary tree. Finally, the propose protocol analysis show that the proposed protocol not only can reduces the authentication signaling which generated in between the MTC devices and the core network but also can manages the MTC devices, efficiently.

Effects of Starvation on Lipid Metabolism and Gluconeogenesis in Yak

  • Yu, Xiaoqiang;Peng, Quanhui;Luo, Xiaolin;An, Tianwu;Guan, Jiuqiang;Wang, Zhisheng
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.11
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    • pp.1593-1600
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    • 2016
  • This research was conducted to investigate the physiological consequences of undernourished yak. Twelve Maiwa yak ($110.3{\pm}5.85kg$) were randomly divided into two groups (baseline and starvation group). The yak of baseline group were slaughtered at day 0, while the other group of yak were kept in shed without feed but allowed free access to water, salt and free movement for 9 days. Blood samples of the starvation group were collected on day 0, 1, 2, 3, 5, 7, 9 and the starved yak were slaughtered after the final blood sample collection. The liver and muscle glycogen of the starvation group decreased (p<0.01), and the lipid content also decreased while the content of moisture and ash increased (p<0.05) both in Longissimus dorsi and liver compared with the baseline group. The plasma insulin and glucose of the starved yak decreased at first and then kept stable but at a relatively lower level during the following days (p<0.01). On the contrary, the non-esterified fatty acids was increased (p<0.01). Beyond our expectation, the ketone bodies of ${\beta}$-hydroxybutyric acid and acetoacetic acid decreased with prolonged starvation (p<0.01). Furthermore, the mRNA expression of lipogenetic enzyme fatty acid synthase and lipoprotein lipase in subcutaneous adipose tissue of starved yak were down-regulated (p<0.01), whereas the mRNA expression of lipolytic enzyme carnitine palmitoyltransferase-1 and hormone sensitive lipase were up-regulated (p<0.01) after 9 days of starvation. The phosphoenolpyruvate carboxykinase and pyruvate carboxylase, responsible for hepatic gluconeogenesis were up-regulated (p<0.01). It was concluded that yak derive energy by gluconeogenesis promotion and fat storage mobilization during starvation but without ketone body accumulation in the plasma.

A study on advanced Kerberos Authentication between Realms based on PKINIT (PKINIT기반의 향상된 Kerberos 인증에 관한 연구)

  • 신광철;정진욱
    • Journal of the Korea Computer Industry Society
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    • v.2 no.12
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    • pp.1541-1548
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    • 2001
  • In this paper, We propose a new Kerberos certification mechanism that improve certification service based on PKINIT that announce in IETF CAT Working Group. Certification between area connected by chain through PKINIT that use X.509 and DS/DNS mutually for service. In order to provide regional services used private key and public key, X.509 of PKINIT is employed on session part and Kerberos's private key on actual authentication part. New mechanism be reduced communication overload doing to simplify certification formality between Client and remote KDC by KDC's certificate use to get ticket in remote sacred ground and remote KDC's reaffirmation process omitted.

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Implementation of key establishment protocol using Signcryption for Secure RTP

  • Kim, Hyung-Chan;Kim, Jong-Won;Lee, Dong-Ik
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.10c
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    • pp.439-441
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    • 2002
  • Real-time Transport Protocol (RTP) is widely used in VoIP stacks charging the multimedia data delivery. Concerning with payload protection of RTP packets, Secure RTP has been discussed in IETF AVT group to provide confidentiality and authentication features using block ciphering and message authentication coding. However, Secure RTP only concentrates on payload protection. Signcryption is a good candidate for key agreement. This paper proposes a key establishment protocol using Signcryption and shows example implementation of a secure VoIP application based on Secure RTP with the proposed scheme.

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Height-thickness ratio on axial behavior of composite wall with truss connector

  • Qin, Ying;Shu, Gan-Ping;Zhou, Xiong-Liang;Han, Jian-Hong;He, Yun-Fei
    • Steel and Composite Structures
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    • v.30 no.4
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    • pp.315-325
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    • 2019
  • Double skin composite walls offer structural and economic merits over conventional reinforced concrete counterparts in terms of higher capacity, greater stiffness, and better ductility. This paper investigated the axial behavior of double skin composite walls with steel truss connectors. Full-scaled tests were conducted on three specimens with different height-to-thickness ratios. Test results were evaluated in terms of failure mode, load-axial displacement response, buckling loading, axial stiffness, ductility, strength index, load-lateral deflection, and strain distribution. The test data were compared with AISC 360 and Eurocode 4 and it was found that both codes provided conservative predictions on the safe side.

Prognostic Model Built on Blood-based Biomarkers in Patients with Metastatic Colorectal Cancer

  • He, Wen-Zhuo;Jiang, Chang;Yin, Chen-Xi;Guo, Gui-Fang;Rong, Ru-Ming;Qiu, Hui-Juan;Chen, Xu-Xian;Zhang, Bei;Xia, Liang-Ping
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.17
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    • pp.7327-7331
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    • 2014
  • Background: We had previously showed that the neutrophil lymphocyte ratio (NLR), ${\gamma}$-glutamyl transpeptidase (GGT) and carcinoembryonic antigen (CEA) are prognostic factors for metastatic colorectal cancer (mCRC) patients. In this study we developed a prognostic model based on these three indices. Materials and Methods: A total of 243 patients who were initially diagnosed as mCRC between 2005 and 2010 in the Sun Yat-sen University Cancer Center were studied. The endpoint was overall survival (OS). Results: NLR>3, elevated GGT and elevated CEA were confirmed as independent risk factors which could predict poor prognosis. Patients could be divided into three groups according to the number of risk factors they had. Those with two or three were defined as the high risk group, individuals with one risk factor as the modest risk group and patients without risk factor as the low risk group. The OS values for these three groups were 16.2 months (2.80~68.8), 24.2 months (4.07~79.0), and 37.2 months (12.6~87.8), respectively (p<0.001). Conclusions: We developed a simple but useful model based on NLR, GGT and CEA to provide prognostic information to clinical practice in highly selected mCRC patients. Further prospective and multi-center studies are warranted to test our model.

Yeast Surface Display of Capsid Protein VP7 of Grass Carp Reovirus: Fundamental Investigation for the Development of Vaccine Against Hemorrhagic Disease

  • Luo, Shaoxiang;Yan, Liming;Zhang, Xiaohua;Yuan, Li;Fang, Qin;Zhang, Yong-An;Dai, Heping
    • Journal of Microbiology and Biotechnology
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    • v.25 no.12
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    • pp.2135-2145
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    • 2015
  • VP7, an outer capsid protein of grass carp reovirus (GCRV), was expressed and displayed on the surface of Saccharomyces cerevisiae for developing an efficient vaccine against hemorrhagic disease of grass carp. The result of flow cytometry analysis indicated that protein VP7 could be displayed on the surface of yeast cells after inducing with galactose. The expression of VP7 was confirmed by western blot analysis and further visualized with confocal microscopy. The specific antibodies against VP7 generated from mice were detectable from all immune groups except the control group, which was immunized with untransformed yeast cells. The displaying VP7 on glycosylation-deficient strain EBYΔMnn9 was detected to induce a relatively low level of specific antibody amongst the three strains. However, the antiserum of EBYΔM9-VP7 showed relative high capacity to neutralize GCRV. Further neutralization testing assays indicated that the neutralizing ability of antiserum of the EBYΔM9-VP7 group appeared concentration dependent, and could be up to 66.7% when the antiserum was diluted to 1:50. This result indicates that appropriate gene modification of glycosylation in a yeast strain has essential effect on the immunogenicity of a yeast-based vaccine.

Solving the Discrete Logarithm Problem for Ephemeral Keys in Chang and Chang Password Key Exchange Protocol

  • Padmavathy, R.;Bhagvati, Chakravarthy
    • Journal of Information Processing Systems
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    • v.6 no.3
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    • pp.335-346
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    • 2010
  • The present study investigates the difficulty of solving the mathematical problem, namely the DLP (Discrete Logarithm Problem) for ephemeral keys. The DLP is the basis for many public key cryptosystems. The ephemeral keys are used in such systems to ensure security. The DLP defined on a prime field $Z^*_p of random prime is considered in the present study. The most effective method to solve the DLP is the ICM (Index Calculus Method). In the present study, an efficient way of computing the DLP for ephemeral keys by using a new variant of the ICM when the factors of p-1 are known and small is proposed. The ICM has two steps, a pre-computation and an individual logarithm computation. The pre-computation step is to compute the logarithms of a subset of a group and the individual logarithm step is to find the DLP using the precomputed logarithms. Since the ephemeral keys are dynamic and change for every session, once the logarithms of a subset of a group are known, the DLP for the ephemeral key can be obtained using the individual logarithm step. Therefore, an efficient way of solving the individual logarithm step based on the newly proposed precomputation method is presented and the performance is analyzed using a comprehensive set of experiments. The ephemeral keys are also solved by using other methods, which are efficient on random primes, such as the Pohlig-Hellman method, the Van Oorschot method and the traditional individual logarithm step. The results are compared with the newly proposed individual logarithm step of the ICM. Also, the DLP of ephemeral keys used in a popular password key exchange protocol known as Chang and Chang are computed and reported to launch key recovery attack.

Stem Rot on Adzuki Bean (Vigna angularis) Caused by Rhizoctonia solani AG 4 HGI in China

  • Sun, Suli;Xia, Changjian;Zhang, Jiqing;Duan, Canxing;Wang, Xiaoming;Wu, Xiaofei;Lee, Suk-Ha;Zhu, Zhendong
    • The Plant Pathology Journal
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    • v.31 no.1
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    • pp.67-71
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    • 2015
  • During late August and early September 2011, stem rot symptoms were observed on adzuki bean plants (Vigna angularis) growing in fields located in Beijing and Hebei Province, China, respectively. In this study, four isolates were obtained from infected stems of adzuki bean plants. Based on their morphology, and sequence and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses of the ribosomal DNA internal transcribed spacers (rDNA-ITS) region, the four isolates were identified as Rhizoctonia solani in anastomosis group (AG) 4 HGI. Pathogenicity tests showed that all isolates were strongly pathogenic to adzuki bean and resulted in serious wilt symptoms which was similar to observations in the fields. Additionally, the isolates infected several other crops and induced related rot on the roots and basal stems. To our knowledge, this is the first report of Rhizoctonia solani AG 4 HGI causing stem rot on adzuki bean.

Proteomic Analysis of the Aging-related Proteins in Human Normal Colon Epithelial Tissue

  • Li, Ming;Xiao, Zhi-Qiang;Chen, Zhu-Chu;Li, Jian-Ling;Li, Cui;Zhang, Peng-Fei;Li, Mao-Yu
    • BMB Reports
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    • v.40 no.1
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    • pp.72-81
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    • 2007
  • In order to screen the aging related proteins in human normal colon epithelia, the comparative proteomics analysis was applied to get the two-dimensional electrophoresis (2-DE) profiles with high resolution and reproducibility from normal colon epithelial tissues of young and aged people. Differential proteins between the colon epithelia of two age groups were found with PDQuest software. The thirty five differential protein-spots were identified by peptide mass fingerprint (PMF) based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) and database searching. Among them there are sixteen proteins which are significantly up-regulated in the colonic mucosal epithelia of young people group, which include ATP synthase beta chain, electron transfer flavoprotein alpha-subunit, catalase, glutathione peroxidase 1, annexin A2 and heat shock cognate 71 kDa protein, etc.; There are nineteen proteins which are significantly up-regulated in the colonic mucosal epithelia of aged people group, which include far upstream element-binding protein 1, nucleoside diphosphate kinase B, protein disulfide-isomerase precursor and VDAC-2, etc.. The identified differential proteins appear to be involved in metabolism, energy generation, chaperone, antioxidation, signal transduction, protein folding and apoptosis. The data will help to understand the molecular mechanisms of human colon epithelial aging.