• Title/Summary/Keyword: Collusion

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PEC: A Privacy-Preserving Emergency Call Scheme for Mobile Healthcare Social Networks

  • Liang, Xiaohui;Lu, Rongxing;Chen, Le;Lin, Xiaodong;Shen, Xuemin (Sherman)
    • Journal of Communications and Networks
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    • v.13 no.2
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    • pp.102-112
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    • 2011
  • In this paper, we propose a privacy-preserving emergency call scheme, called PEC, enabling patients in life-threatening emergencies to fast and accurately transmit emergency data to the nearby helpers via mobile healthcare social networks (MHSNs). Once an emergency happens, the personal digital assistant (PDA) of the patient runs the PEC to collect the emergency data including emergency location, patient health record, as well as patient physiological condition. The PEC then generates an emergency call with the emergency data inside and epidemically disseminates it to every user in the patient's neighborhood. If a physician happens to be nearby, the PEC ensures the time used to notify the physician of the emergency is the shortest. We show via theoretical analysis that the PEC is able to provide fine-grained access control on the emergency data, where the access policy is set by patients themselves. Moreover, the PEC can withstandmultiple types of attacks, such as identity theft attack, forgery attack, and collusion attack. We also devise an effective revocation mechanism to make the revocable PEC (rPEC) resistant to inside attacks. In addition, we demonstrate via simulation that the PEC can significantly reduce the response time of emergency care in MHSNs.

Interplay between Epigenetics and Genetics in Cancer

  • Choi, Jae Duk;Lee, Jong-Soo
    • Genomics & Informatics
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    • v.11 no.4
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    • pp.164-173
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    • 2013
  • Genomic instability, which occurs through both genetic mechanisms (underlying inheritable phenotypic variations caused by DNA sequence-dependent alterations, such as mutation, deletion, insertion, inversion, translocation, and chromosomal aneuploidy) and epigenomic aberrations (underlying inheritable phenotypic variations caused by DNA sequence-independent alterations caused by a change of chromatin structure, such as DNA methylation and histone modifications), is known to promote tumorigenesis and tumor progression. Mechanisms involve both genomic instability and epigenomic aberrations that lose or gain the function of genes that impinge on tumor suppression/prevention or oncogenesis. Growing evidence points to an epigenome-wide disruption that involves large-scale DNA hypomethylation but specific hyper-methylation of tumor suppressor genes, large blocks of aberrant histone modifications, and abnormal miRNA expression profile. Emerging molecular details regarding the modulation of these epigenetic events in cancer are used to illustrate the alterations of epigenetic molecules, and their consequent malfunctions could contribute to cancer biology. More recently, intriguing evidence supporting that genetic and epigenetic mechanisms are not separate events in cancer has been emerging; they intertwine and take advantage of each other during tumorigenesis. In addition, we discuss the collusion between epigenetics and genetics mediated by heterochromatin protein 1, a major component of heterochromatin, in order to maintain genome integrity.

Communication at the End of Life

  • Onishi, Hideki
    • Journal of Hospice and Palliative Care
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    • v.24 no.3
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    • pp.135-143
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    • 2021
  • End-of-life patients experience physical, mental, social, and existential distress. While medical personnel provide medication and care to alleviate patients' distress, listening to and interacting with patients remains essential for understanding their psychological condition. The most important tool, though difficult to implement in practice, is end-of-life discussion (EOLD). EOLD has been shown to have positive effects on end-of-life treatment choices, achievement of patients' life goals, improvements in the quality of life of patients and their families, and the prevention of depression and complicated grief among bereaved family members. EOLD is not often undertaken in clinical practice, however, due to hesitancy among medical personnel and patients for various reasons. In order to conduct an EOLD, the patient's judgment, psychiatric illnesses such as delirium and depression, and psychological issues such as the side effects of psychotropic drugs, denial, and collusion must be evaluated. Open and honest conversation, treatment goal setting, the doctor's familiarity with the patient's background, and attentiveness when providing information are important elements for any dialogue. Meaning-centered psychotherapy was developed to alleviate the existential distress of cancer patients, and its application may promote EOLD. The future development of meaning-centered psychotherapy in practice and in research is expected to further promote EOLD.

A Group Key Management Scheme for WSN Based on Lagrange Interpolation Polynomial Characteristic

  • Wang, Xiaogang;Shi, Weiren;Liu, Dan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.7
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    • pp.3690-3713
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    • 2019
  • According to the main group key management schemes logical key hierarchy (LKH), exclusion basis systems (EBS) and other group key schemes are limited in network structure, collusion attack, high energy consumption, and the single point of failure, this paper presents a group key management scheme for wireless sensor networks based on Lagrange interpolation polynomial characteristic (AGKMS). That Chinese remainder theorem is turned into a Lagrange interpolation polynomial based on the function property of Chinese remainder theorem firstly. And then the base station (BS) generates a Lagrange interpolation polynomial function f(x) and turns it to be a mix-function f(x)' based on the key information m(i) of node i. In the end, node i can obtain the group key K by receiving the message f(m(i))' from the cluster head node j. The analysis results of safety performance show that AGKMS has good network security, key independence, anti-capture, low storage cost, low computation cost, and good scalability.

A Study on An Enhancement Scheme of Privacy and Anonymity through Convergence of Security Mechanisms in Blockchain Environments (블록체인 환경에서 보안 기법들의 융합을 통한 프라이버시 및 익명성 강화 기법에 대한 연구)

  • Kang, Yong-Hyeog
    • Journal of the Korea Convergence Society
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    • v.9 no.11
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    • pp.75-81
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    • 2018
  • Anonymity and privacy issues are becoming important as all transactions in the blockchain are open to users. Public blockchains appear to guarantee anonymity by using public-key addresses on behalf of users, but they can weaken anonymity by tracking with various analytic techniques based on transaction graph. In this paper, we propose a scheme to protect anonymity and privacy by converging various security techniques such as k-anonymity, mixing, blind signature, multi-phase processing, random selection, and zero-knowledge proof techniques with incentive mechanism and contributor participation. Through performance analysis, our proposed scheme shows that it is difficult to invade privacy and anonymity through collusion attacks if the number of contributors is larger than that of conspirators.

Listed Local State-Owned Enterprises and Environmental Performance: Evidence from China

  • TANG, Kai;BAE, Khee Su
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.2
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    • pp.255-262
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    • 2021
  • The paper examines the influence of ownership type on environmental performance of Chinese listed enterprises. China's environmental problems are attributed to the collusion between enterprises and economy-oriented local governments, which has allowed many companies to skirt environmental regulations. Especially, local state-owned enterprises (SOEs) tend to have worse environmental performance than private firms, under the wing of local governments, with whom they have a closer political connection. According to the report of the Environmental Protection Agency, currently the unacceptably poor environmental performance of local SOEs has severely hampered the realization of green economy in China. After examining the dataset of 15,996 firm-year observations from 2,688 listed firms, this paper found that, in the presence of central government supervision and personnel intervention, listed local SOEs will be forced to improve their environmental performance in accordance with standards set by the central government, which leads to better environmental performance than that of listed private firms (private firms). The result of two-stage regression also supports the conclusion. This shows increased supervision and personnel intervention from the central government can significantly improve the environmental performance of local SOEs. The research in this paper expects to make a contribution to attaining the goal of green economy in China.

Cryptanalysis of ID-based Group Signature (그룹 식별 정보를 이용한 그룹 서명 방식의 암호 분석)

  • 박상준;원동호
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.7 no.2
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    • pp.11-18
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    • 1997
  • Chaum and Heyst first proposed group signature which is based on the undeniable signature. So, a receiver of the signature can't verify a group signature without cooperation of the signer and, in case of dispute later on, he can't reveal the identity of the signer without help of the group members. Park et. al. proposed an id-based group signature with self-authentication, in which the receiver of the signature reveals the identity of the signer without help of the group members. However, the proposed scheme has two problem : 1) the receiver can't identify the signer, since every keys of the group members hold the identification procedure. 2) By collusion of the group members, new secret key for a group signature can be computed and the secret key of the trusted center can be revealed.

An efficient sealed-bid auction protocol (효율적인 sealed-bid 경매 프로토콜)

  • 신상욱;류희수
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.12 no.6
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    • pp.3-15
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    • 2002
  • In this paper, we propose an efficient and secure sealed-bid auction protocol with two servers, a seller S and a third party A . The proposed scheme uses the idea of the conditional oblivious transfer protocol proposed by Crescenzo-Ostrovskey-Rajagopalan. A server A is not a trusted third party, but is assumed not to collude with a server S. In the proposed auction protocol, barring collusion between A and S, neither party gains any information about the bids, and moreover, the outcome of the auction will be correct. And the computational complexity of our auction protocol is considerably efficient and the communication overhead is similar to that of Naor-Pinkas-Sumner's scheme.

A Study on Tracing-Threshold of Public-Key Traitor-Tracing Schemes (공개키 기반의 공모자 추적기법에서의 추적 임계치에 관한 연구)

  • 임정미;이병선;박창섭
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.13 no.6
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    • pp.121-127
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    • 2003
  • The threshold value of the traitor-tracing schemes means a maximum number of traitors whose identities can be uniquely exposed using the tracing scheme. In the traitor-tracing scheme based on an error-correcting code, which is focused at this paper, the threshold value is determined by the error-correcting capability of the underlying error-correcting code. Analyzed in terms of a combinatorial property of the tracing scheme is the resulting effect on the tracing scheme when the collusion size is over the threshold value, and a possibility of two disjoint groups of users making an identical unauthorized decryption key is shown.

Efficient Proxy Re-encryption Scheme for E-Voting System

  • Li, Wenchao;Xiong, Hu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.5
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    • pp.1847-1870
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    • 2021
  • With the development of information and communication technologies, especially wireless networks and cell phones, the e-voting system becomes popular as its cost-effectiveness, swiftness, scalability, and ecological sustainability. However, the current e-voting schemes are faced with the problem of privacy leakage and further cause worse vote-buying and voter-coercion problems. Moreover, in large-scale voting, some previous e-voting system encryption scheme with pairing operation also brings huge overhead pressure to the voting system. Thus, it is a vital problem to design a protocol that can protect voter privacy and simultaneously has high efficiency to guarantee the effective implementation of e-voting. To address these problems, our paper proposes an efficient unidirectional proxy re-encryption scheme that provides the re-encryption of vote content and the verification of users' identity. This function can be exactly applied in the e-voting system to protect the content of vote and preserve the privacy of the voter. Our proposal is proven to be CCA secure and collusion resistant. The detailed analysis also shows that our scheme achieves higher efficiency in computation cost and ciphertext size than the schemes in related fields.