• 제목/요약/키워드: Multi-user

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A Method of Risk Assessment for Multi-Factor Authentication

  • Kim, Jae-Jung;Hong, Seng-Phil
    • Journal of Information Processing Systems
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    • 제7권1호
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    • pp.187-198
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    • 2011
  • User authentication refers to user identification based on something a user knows, something a user has, something a user is or something the user does; it can also take place based on a combination of two or more of such factors. With the increasingly diverse risks in online environments, user authentication methods are also becoming more diversified. This research analyzes user authentication methods being used in various online environments, such as web portals, electronic transactions, financial services and e-government, to identify the characteristics and issues of such authentication methods in order to present a user authentication level system model suitable for different online services. The results of our method are confirmed through a risk assessment and we verify its safety using the testing method presented in OWASP and NIST SP800-63.

The Effects of Multi-Modality on the Use of Smart Phones

  • Lee, Gaeun;Kim, Seongmin;Choe, Jaeho;Jung, Eui Seung
    • 대한인간공학회지
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    • 제33권3호
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    • pp.241-253
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    • 2014
  • Objective: The objective of this study was to examine multi-modal interaction effects of input-mode switching on the use of smart phones. Background: Multi-modal is considered as an efficient alternative for input and output of information in mobile environments. However, there are various limitations in current mobile UI (User Interface) system that overlooks the transition between different modes or the usability of a combination of multi modal uses. Method: A pre-survey determined five representative tasks from smart phone tasks by their functions. The first experiment involved the use of a uni-mode for five single tasks; the second experiment involved the use of a multi-mode for three dual tasks. The dependent variables were user preference and task completion time. The independent variable in the first experiment was the type of modes (i.e., Touch, Pen, or Voice) while the variable in the second experiment was the type of tasks (i.e., internet searching, subway map, memo, gallery, and application store). Results: In the first experiment, there was no difference between the uses of pen and touch devices. However, a specific mode type was preferred depending on the functional characteristics of the tasks. In the second experiment, analysis of results showed that user preference depended on the order and combination of modes. Even with the transition of modes, users preferred the use of multi-modes including voice. Conclusion: The order of combination of modes may affect the usability of multi-modes. Therefore, when designing a multi-modal system, the fact that there are frequent transitions between various mobile contents in different modes should be properly considered. Application: It may be utilized as a user-centered design guideline for mobile multi modal UI system.

Protection Management for Guaranteed User-Driven Virtual Circuit Services in Dynamic Multi-domain Environments: Design Issues and Challenges

  • Lim, Huhnkuk
    • ETRI Journal
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    • 제37권2호
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    • pp.369-379
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    • 2015
  • Fault management of virtualized network environments using user-driven network provisioning systems (NPSs) is crucial for guaranteeing seamless virtual network services irrespective of physical infrastructure impairment. The network service interface (NSI) of the Open Grid Forum reflects the need for a common standard management API for the reservation and provisioning of user-driven virtual circuits (VCs) across global networks. NSI-based NPSs (that is, network service agents) can be used to compose user-driven VCs for mission-critical applications in a dynamic multi-domain. In this article, we first attempt to outline the design issues and challenges faced when attempting to provide mission-critical applications using dynamic VCs with a protection that is both user-driven and trustworthy in a dynamic multi-domain environment, to motivate work in this area of research. We also survey representative works that address inter-domain VC protection and qualitatively evaluate them and current NSI against the issues and challenges.

멀티서버를 위한 안전한 동적 ID 기반 원격 사용자 인증 방식에 대한 안전성 분석 (Security Analysis of a Secure Dynamic ID based Remote User Authentication Scheme for Multi-server Environment)

  • 양형규
    • 한국인터넷방송통신학회논문지
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    • 제13권1호
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    • pp.273-278
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    • 2013
  • 최근에, 멀티서버 환경을 위한 스마트 카드를 이용한 사용자 인증 방식이 실질적인 응용 분야에서 적용되고 있다. 2009년도에 Liao-Wang은 멀티서버를 위한 안전한 동적 ID 기반 원격 사용자 인증 방식을 제안하였다. 이 방식은 여러 종류의 가능한 공격에 안전하면서 사용자 익명성 보장하였다. 본 논문에서 우리는 Liao-Wang의 방식에 대한 안정성을 분석하고, Liao-Wang의 방식이 위조 공격, 패스워트 추측 공격, 세션키 공격 그리고 내부자 공격에 취약하다는 것을 보여준다. 추가로 Liao-Wang의 방식이 사용자와 서버간의 사용자 익명성 역시 제공하지 못한다는 것을 증명한다.

멀티모드 단말기를 위한 셀 경계 지역에서의 SINR 기반 사용자 선택 방법 (Scheduling Method based on SINR at Cell Edge for multi-mode mobile device)

  • 금동현;최승원
    • 디지털산업정보학회논문지
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    • 제11권3호
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    • pp.63-68
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    • 2015
  • We consider a cell edge environment. In cell edge, a user interfered by signal which is generated by a base stations not including the user. In cell edge environment, that is, there are inter cell interference (ICI) as well as multi user interference (MUI). Coordinated multi-point transmission (CoMP) is a technique which mitigates ICI between base stations. In CoMP, therefore, base stations can coordinate with each other by sharing user state information (CSI) in order to mitigate ICI. To improve sum rate performance in CoMP, each base station should generate optimal user group and transmit data to users selected in the optimal user group. In this paper, we propose a user selection algorithm in CoMP. The proposed method use signal to interference plus noise ratio (SINR) as criterion of selecting users. Because base station can't measure accurate SINR of users, in this paper, we estimate SINR equation considering ICI as well as MUI. Also, we propose a user selection algorithm based on the estimated SINR. Through MATAL simulation, we verify that the proposed method improves the system sum rate by an average of 1.5 ~ 3 bps/Hz compared to the conventional method.

Improving Security and Privacy-Preserving in Multi-Authorities Ciphertext-Policy Attribute-Based Encryption

  • Hu, Shengzhou;Li, Jiguo;Zhang, Yichen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권10호
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    • pp.5100-5119
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    • 2018
  • Most of existing privacy-preserving multi-authorities attribute-based encryption schemes (PP-MA-ABE) only considers the privacy of the user identity (ID). However, in many occasions information leakage is caused by the disclosing of his/her some sensitive attributes. In this paper, we propose a collusion-resisting ciphertext-policy PP-MA-ABE (CRPP-MACP-ABE) scheme with hiding both user's ID and attributes in the cloud storage system. We present a method to depict anonymous users and introduce a managerial role denoted by IDM for the management of user's anonymous identity certificate ($AID_{Cred}$). The scheme uses $AID_{Cred}$ to realize privacy-preserving of the user, namely, by verifying which attribute authorities (AAs) obtain the blinded public attribute keys, pseudonyms involved in the $AID_{Cred}$ and then distributes corresponding private keys for the user. We use different pseudonyms of the user to resist the collusion attack launched by viciousAAs. In addition, we utilize IDM to cooperate with multiple authorities in producing consistent private key for the user to avoid the collusion attack launched by vicious users. The proposed CRPP-MACP-ABE scheme is proved secure. Some computation and communication costs in our scheme are finished in preparation phase (i.e. user registration). Compared with the existing schemes, our scheme is more efficient.

A Multi-Modal Complex Motion Authoring Tool for Creating Robot Contents

  • Seok, Kwang-Ho;Kim, Yoon-Sang
    • 한국멀티미디어학회논문지
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    • 제13권6호
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    • pp.924-932
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    • 2010
  • This paper proposes a multi-modal complex motion authoring tool for creating robot contents. The proposed tool is user-friendly and allows general users without much knowledge about robots, including children, women and the elderly, to easily edit and modify robot contents. Furthermore, the tool uses multi-modal data including graphic motion, voice and music to simulate user-created robot contents in the 3D virtual environment. This allows the user to not only view the authoring process in real time but also transmit the final authored contents to control the robot. The validity of the proposed tool was examined based on simulations using the authored multi-modal complex motion robot contents as well as experiments of actual robot motions.

A Collaborative Visual Language

  • Kim, Kyung-Deok
    • Journal of information and communication convergence engineering
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    • 제1권2호
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    • pp.74-81
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    • 2003
  • There are many researches on visual languages, but the most of them are difficult to support various collaborative interactions on a distributed multimedia environment. So, this paper suggests a collaborative visual language for interaction between multi-users. The visual language can describe a conceptual model for collaborative interactions between multi-users. Using the visual language, generated visual sentences consist of object icons and interaction operators. An object icon represents a user who is responsible for a collaborative activity, has dynamic attributes of a user, and supports flexible interaction between multi-users. An interaction operator represents an interactive relation between multi-users and supports various collaborative interactions. Merits of the visual language are as follows: supporting of both asynchronous interaction and synchronous interaction, supporting flexible interaction between multi-users according to participation or leave of users, supporting a user oriented modeling, etc. For example, an application to a workflow system for document approval is illustrated. So we could be found that the visual language shows a collaborative interaction.

스마트 복약관리 및 모니터링 시스템에서 다중 사용자 인증 방법 (A Multi-User Authentication Scheme for a Smart Medication Management and Monitoring System)

  • 김범준
    • 한국전자통신학회논문지
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    • 제10권5호
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    • pp.571-578
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    • 2015
  • 장기 투약이 필요한 만성질환자에 대해서는 직접복약관리가 가장 확실한 방법임에도 불구하고 인적, 경제적 비용으로 인하여 실제 적용하는 것은 쉽지 않은 일이다. 이에 대한 대안으로 등장한 IT기술 기반의 스마트 복약관리 및 모니터링 시스템은 이의 구현을 위해서 특별한 장치의 도움을 요구한다. 본 논문에서는 이 장치의 역할을 수행하기 위해서 개발된 스마트 약상자를 여러 환자가 공유하기 위한 인증 절차를 제안한다. 본 논문에서 제안하는 인증 절차를 통해서 스마트 약상자가 장기 투약이 필요한 환자로 하여금 올바르게 약을 복용하도록 하여 완치율을 높이는 데 기여할 수 있을 것으로 기대된다.

사용자 입력 문자에 반응하는 군집 로봇 행동 구현 (Behavior Realization of Multi-Robots Responding to User's Input Characters)

  • 조영래;이길호;조성호;신인식
    • 제어로봇시스템학회논문지
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    • 제18권5호
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    • pp.419-425
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    • 2012
  • This paper presents an approach to implement the behaviors of multi-robots responding to user's input characters. The robots are appropriately displaced to express any input characters. Using our method, any user can easily and friendly control multirobots. The responses of the robots to the user's input are intuitive. We utilize the centroidal Voronoi algorithm and the continuoustime Lloyd algorithm, which have popularly been used for the optimal sensing coverage problems. Collision protection is considered to be applied for real robots. LED sensors are used to identify positions of multi-robots. Our approach is evaluated through experiments with five mobile robots. When a user draw alphabets, the robots are deployed correspondingly. By checking position errors, the feasibility of our method is validated.