• Title/Summary/Keyword: Consensus Protocol

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The Blockchain based Undeniable Multi-Signature Scheme for Protection of Multiple Authorship on Wisdom Contents (지혜콘텐츠 공동저작권 보호에 적합한 블록체인 기반 부인봉쇄 다중서명 기법)

  • Yun, Sunghyun
    • Journal of Internet of Things and Convergence
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    • v.7 no.2
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    • pp.7-12
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    • 2021
  • Wisdom Contents are created with experiences and ideas of multiple authors, and consumed in Internet based Social Network Services that are not subjected to regional restrictions. Existing copyright management systems are designed for the protection of professional authors' rights, and effective in domestic area. On the contrary, the blockchain protocol is subjected to the service and the block is added by the consensus of participating nodes. If the data is stored to the blockchain, it cannot be modified or deleted. In this paper, we propose the blockchain based undeniable multi-signature scheme for the protection of multiple authorship on Wizdom Contents. The proposed scheme is consisted of co-authors' common public key generation, multi-signature generation and verification protocols. In the undeniable signature scheme, the signature cannot be verified without help of the signer. The proposed scheme is best suited to the contents purchase protocol. All co-authors cannot deny the fairness of the automated profit distribution through the verification of multiple authorship on Wizdom Contents.

Privacy-Preserving Cloud Data Security: Integrating the Novel Opacus Encryption and Blockchain Key Management

  • S. Poorani;R. Anitha
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.11
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    • pp.3182-3203
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    • 2023
  • With the growing adoption of cloud-based technologies, maintaining the privacy and security of cloud data has become a pressing issue. Privacy-preserving encryption schemes are a promising approach for achieving cloud data security, but they require careful design and implementation to be effective. The integrated approach to cloud data security that we suggest in this work uses CogniGate: the orchestrated permissions protocol, index trees, blockchain key management, and unique Opacus encryption. Opacus encryption is a novel homomorphic encryption scheme that enables computation on encrypted data, making it a powerful tool for cloud data security. CogniGate Protocol enables more flexibility and control over access to cloud data by allowing for fine-grained limitations on access depending on user parameters. Index trees provide an efficient data structure for storing and retrieving encrypted data, while blockchain key management ensures the secure and decentralized storage of encryption keys. Performance evaluation focuses on key aspects, including computation cost for the data owner, computation cost for data sharers, the average time cost of index construction, query consumption for data providers, and time cost in key generation. The results highlight that the integrated approach safeguards cloud data while preserving privacy, maintaining usability, and demonstrating high performance. In addition, we explore the role of differential privacy in our integrated approach, showing how it can be used to further enhance privacy protection without compromising performance. We also discuss the key management challenges associated with our approach and propose a novel blockchain-based key management system that leverages smart contracts and consensus mechanisms to ensure the secure and decentralized storage of encryption keys.

E-mail System Model based on Ethereum (이더리움 기반 이메일 시스템 모델)

  • Kim, Taekyung
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.13 no.4
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    • pp.99-106
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    • 2017
  • With the advent of virtual money such as bit coins, interest in the block chain is increasing. Block Chain is a technology that supports Distributed Ledger and is a versatile technology applicable to various fields. Currently, the block chain is conducting research for various applications such as virtual money, trade finance, marketplace, power market, image contents service, and IoT. The technologies that make up the block chain are smart contract, digital signature/hash function and consensus algorithm. And these technologies operate on P2P networks. In this paper, we have studied e-mail system based on the ethereum which is one of the block chain based technologies. Most legacy mail systems use SMTP and the POP3/IMAP protocol to send and receive e-mail, and e-mail use S/MIME to protect the e-mail. However, S/MIME is vulnerable to DDoS attacks because it is configured centrally. And it also does not provide non-repudiation of mail reception. To overcome these weaknesses, we proposed an e-mail system model based on ethereum. The proposed model is able to cope with DDoS attack and forgery prevention by using block chain based technology, and reliable recording and management among block chain participants are provided, so that it is possible to provide a non-repudiation function of e-mail transmission and reception.

Current status of surgery first approach (part II): precautions and complications

  • Kwon, Tae-Geon;Han, Michael D.
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.41
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    • pp.23.1-23.10
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    • 2019
  • The choice of surgical technique in orthognathic surgery is based primarily on the surgical treatment objectives (STO), which is a fundamental component of the orthognathic treatment process. In the conventional orthodontics-first approach, presurgical planning can be performed twice, during the preorthodontic (initial STO) and presurgical phases (final STO). Recently, a surgery-first orthognathic approach (SFA) without presurgical orthodontic treatment has been introduced and combined initial and final STO at the same time. In contrast to the conventional surgical-orthodontic treatment protocol that includes preoperative orthodontics for dental decompensations to maximize stable postoperative occlusion, the SFA potentially shortens the treatment period and minimizes esthetic concerns during the decompensation period because skeletal problems are corrected from the beginning. The indications for the SFA have been proposed in the literature, but no consensus exists. Moreover, because dental occlusion of the pre-orthodontic arches cannot be used as a guide for establishing the surgical treatment plan, there are fundamental limitations in accurate prediction of postsurgical results in the SFA. Recently, the concepts of postsurgical orthodontic treatment are continuously changing and evolving to overcome this inherent limitation of the SFA. The elimination of presurgical orthodontics can change the paradigm of orthognathic surgery but still requires cautious case selection and thorough discussion and collaboration between orthodontists and surgeons regarding the goals and postoperative management of the orthognathic procedure.

Korean Translation of the CARE guidelines (CARE 지침 한국어판 제작)

  • Lee, Seung Min;Shin, Ye Sle;Nam, Dong Woo;Choi, Do Young
    • Journal of Acupuncture Research
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    • v.32 no.4
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    • pp.1-9
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    • 2015
  • Objectives : The aim of this study is to develop the official Korean translation of the CARE guidelines. Methods : CARE guidelines were developed in 2013 though a consensus of experts led by the CARE group. It is the first reporting guideline for case reports that includes a 13-item checklist. We contacted the main author of the original manuscript and obtained permission to develop the Korean translation. The translation process followed a systematic protocol designated by the CARE group which included an independent back translation and confirmation from the original author. Results : The Korean translation of the CARE guidelines was completed with approval from the original author. The Korean checklist is posted on the official website (www.care-statement.org) and the final translation of the manuscript is introduced in this article as an appendix. Conclusions : We hope that this will help introduce the CARE guidelines to Korean authors and other stakeholders, induce a more active use of reporting guidelines, and eventually contribute to the overall improvement of the reporting quality of case reports published in Korean literature.

The Dilemma of Parameterizing Propagation Time in Blockchain P2P Network

  • Rahmadika, Sandi;Noh, Siwan;Lee, Kyeongmo;Kweka, Bruno Joachim;Rhee, Kyung-Hyune
    • Journal of Information Processing Systems
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    • v.16 no.3
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    • pp.699-717
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    • 2020
  • Propagation time on permissionless blockchain plays a significant role in terms of stability and performance in the decentralized systems. A large number of activities are disseminated to the whole nodes in the decentralized peer-to-peer network, thus causing propagation delay. The stability of the system is our concern in the first place. The propagation delay opens up opportunities for attackers to apply their protocol. Either by accelerating or decelerating the propagation time directly without proper calculation, it brings numerous negative impacts to the entire blockchain system. In this paper, we thoroughly review and elaborate on several parameters related to the propagation time in such a system. We describe our findings in terms of data communication, transaction propagation, and the possibility of an interference attack that caused an extra propagation time. Furthermore, we present the influence of block size, consensus, and blockchain scalability, including the relation of parameters. In the last session, we remark several points associated with the propagation time and use cases to avoid dilemmas in the light of the experiments and literary works.

Algorithmic approach to the lymphatic leak after vascular reconstruction: a systematic review

  • Nicksic, Peter John;Condit, Kevin Michael;Nayar, Harry Siva;Michelotti, Brett Foster
    • Archives of Plastic Surgery
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    • v.48 no.4
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    • pp.404-409
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    • 2021
  • Background To date, there are no consensus guidelines for management of lymphatic leak in groin vascular reconstruction patients. The goal of this study is to review the relevant literature to determine alternatives for treatment and to design an evidence-based algorithm to minimize cost and morbidity and maximize efficacy. Methods A systematic review of the literature was conducted per Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. Two independent reviewers applied agreed-upon inclusion and exclusion criteria to eligible records. Studies that included patients who underwent groin dissection for oncologic diagnoses and level 5 data were excluded. Interventions were then categorized by efficacy using predetermined criteria. Results Our search yielded 333 records, of which eight studies were included. In four studies, the success of lymphatic ligation ranged from 75% to 100%, with average days to resolution ranging from 0 to 9. Conservative management in the form of elevation, compression, and bedrest may prolong time to resolution of lymphatic leak (14-24 days) and therefore cost. Conclusions The majority of patients should be offered early operative intervention in the form of lymphatic ligation with or without a primary muscle flap. If the patient is not an operative candidate, a trial of conservative management should be attempted before other nonsurgical interventions.

Total Ankle Arthroplasty Management and Rehabilitation (족관절 인공관절 치환술 후 관리 및 재활)

  • Lee, Kwang-Bok
    • Journal of Korean Foot and Ankle Society
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    • v.26 no.3
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    • pp.118-122
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    • 2022
  • Although total ankle arthroplasty (TAA) has increased considerably in the past ten years, reflecting improvements in implant design and survivorship, the clinical outcomes have been less satisfactory than total hip or total knee arthroplasties. Several issues under debate include postoperative management and rehabilitation in TAA. Especially, there is no consensus or evidence for the most appropriate postoperative management and rehabilitation for patients undergoing TAA. This study was therefore undertaken to suggest appropriate postoperative management and rehabilitation in TAA, after reviewing published articles and focusing on the following topics: prehabilitation, hospital stay, immobilization type and duration, weight-bearing management, pharmacological treatment, and adopted rehabilitation protocols. In previous studies, the postoperative management and rehabilitation proposed depended on the surgeon's preference, the patient's characteristics, and the associated surgical procedures performed after TAA. Nonetheless, our research indicates the best approach is to include a prehabilitation program, immobilization in the early postoperative stage (2~4 weeks), range of motion exercise with partial weight-bearing ambulation, followed by full weight-bearing ambulation after six weeks. Further studies are required to develop a standardized rehabilitation protocol and improve the overall quality of care after TAA.

A Study on Security Enhancement for the Use and Improvement of Blockchain Technology (보안성 강화를 위한 블록체인기술의 활용과 개선방안 연구)

  • Seung Jae Yoo
    • Convergence Security Journal
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    • v.23 no.1
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    • pp.63-68
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    • 2023
  • In this study, in relation to blockchain protocol and network security, we study the configuration of blockchain and encryption key management methods on smart contracts so that we can have a strong level of response to MITM attacks and DoS/DDoS attacks. It is expected that the use of blockchain technology with enhanced security can be activated through respond to data security threats such as MITM through encryption communication protocols and enhanced authentication, node load balancing and distributed DDoS attack response, secure coding and vulnerability scanning, strengthen smart contract security with secure consensus algorithms, access control and authentication through enhanced user authentication and authorization, strengthen the security of cores and nodes, and monitoring system to update other blockchain protocols and enhance security.

Development of a Occupation-Based Bilateral Upper Extremity Training Protocol in a Medical Setting for Stroke Patients (뇌졸중 환자를 대상으로 한 병원 환경에서의 작업 기반 양측성 상지 훈련 프로토콜 개발)

  • Kim, Sun-Ho;Kim, Jung Ran;Park, Hae Yean;Han, A-Reum;Kim, Jong-Bae;Park, Ji-Hyuk
    • Therapeutic Science for Rehabilitation
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    • v.9 no.1
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    • pp.24-44
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    • 2020
  • Objective : To develop an occupation-based bilateral upper extremity training protocol that can be effectively applied in a medical setting Methods : The research process using the delphi technique was carried out in 3 stages. The first stage was an open questionnaire development stage, The first draft is prepared through literature review and open questions were developed through preliminary research based on the draft. The second stage was the delphi survey. Based on the responses of the experts obtained through the open Delphi survey, the adequacy of the training protocol was shown on a Likert 5 point scale. The items were edited and deleted, reconstructed by analyzing the mean and standard deviation, stability, convergence degree, consensus, and content validity ratio through the questionnaire. The third step was the completion of the protocol. After discussions between researchers, the finalized protocol contents were reorganized to complete the occupation-based bilateral upper extremity training protocol for medical setting. Results : The final protocol consisted of 9 items across 3 areas in the occupation-based intervention selection domain and 81 items across 4 areas in the bilateral upper extremity training domain, intervention period, and evaluation. Conclusions : This study suggests an evidence-based method that collects the opinions of occupational therapists in order to use occupation-based activities as interventions in a situation that currently sees occupational therapy primarily performed in hospitals. It is also meaningful that the bilateral upper extremity training can be applied effectively in clinical situations by concretely presenting.