• Journal of KIISE:Computer Systems and Theory
• /
• v.31 no.8
• /
• pp.465-472
• /
• 2004

Proxy signatures is a signature scheme that an original signer delegates one's signature capability to a proxy signer, and then the proxy signer creates a signature on behalf of the original signer. Delegation of authority is a common practice in the real world, in particular, it happens naturally in hierarchical groups such as company, bank and army, etc. In this paper, we propose a new dynamic multi-proxy signature scheme allowing repetitive delegations in a hierarchical group. We adopt multi-proxy signatures to enhance the security of proxy signature. In multi-proxy signatures, plural proxy signers can generate a valid proxy signature collectively on behalf of one original signer. In our scheme, the proxy group is not fixed but constructed dynamically according to some situations. Delegations are processed from higher level to lower level in the hierarchy using delegation tickets. When the original signer wants to delegate one's signature authority, the original signer generates a delegation ticket based on secret sharing and Diffie-Hellman problems. The delegation ticket is shared among proxy signers and then all the proxy signers can generate a valid proxy signature collectively by reconstructing the original signer's delegation ticket. If a certain proxy signer can not attend the proxy signature generating protocol, the proxy signer can also delegate repetitively his partial signature authority to the lower level participants, and then the proxies are constructed dynamically.

• Journal of Convergence for Information Technology
• /
• v.8 no.5
• /
• pp.69-75
• /
• 2018

The purpose of access control is to prevent computing resources from illegal behavior such as leakage, modification, and destruction by unauthorized users. As the cloud computing environment is expanded to resource sharing services using virtualization technology, a new security model and access control technique are required to provide dynamic and secure cloud-based computing services. The virtualization management convergence access control model provides a flexible user authorization function by applying the dynamic privilege assignment function to the role based access control mechanism. In addition, by applying access control mechanism based on security level and rules, we solve the conflict problem in virtual machine system and guarantee the safeness of physical resources. This model will help to build a secure and efficient cloud-based virtualization management system and will be expanded to a mechanism that reflects the multi-level characteristics.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.7 no.12
• /
• pp.955-963
• /
• 2017

Nowadays, fintech becomes the key technology of the mobile banking and payments. Financial market is moved to fintech-based non-face-to-face trade/payment from traditional face-to-face process in Korea. Core of this transition is the smartphones, which have several sensitive sensors for personal identifications such as fingerprint and iris recognition sensors. But it has some originated security risks by data path attacks, for instance, hacking and pharming. Multi-level certification and security systems are applied to avoid these threats effectively, while these protections can be cause of some inconvenience for non-face-to-face certifications and financing processes. In this paper, I confirmed that it have sensible differences correspond with the data connection paths such as WiFi networks and mobile communication networks of the smartphones, and I propose a gradual certification method which alleviates the inconvenience by risk-level definitions of the data-paths.

• The Journal of the Korea Contents Association
• /
• v.18 no.12
• /
• pp.272-280
• /
• 2018

The purpose of this study was to analyze characters and determinant factors of the life satisfaction of the older adults with disabilities so as to provide suggestion for improving the quality of life. I used the data on 8th Panel Survey of Employment for the Disabled(PSED). The total number of respondents was 452, 126 respondents of one-person households and 326 respondents of multi-person households. The data was analyzed using SPSS Win 24.0 program and utilizing $x^2$test, ANOVA, logistic regression analysis. First, The characteristics of older adults with disabilities was man, married, mild disorder, physical external disorder, non-basis living security recipient, unemployment and the level of life satisfaction was 3.27. Second, The one-person households group showed female, non-married, severe disorder, lower acceptance of disability, lower health status, higher help daily living activity, higher discrimination experience, unemployment, lower income, basis living security recipient, lower position than multi-person group. Third, acceptance of disability, health status, social activity, religion were found to have a significant effect on the life satisfaction of one-person households. And acceptance of disability, health status, position were found to have a significant effect on the life satisfaction of multi-person households. Base on the results of this study, suggested for improving the quality of life of the older adults with disabilities.

• Proceedings of the Korean Information Science Society Conference
• /
• 2007.06d
• /
• pp.40-43
• /
• 2007

보안운영체제에서는 등급기반 사용자, 프로세스, 파일에 대한 영역분리 및 등급별 보안관리를 하는 다중등급보안(Multi Level Security)을 구현하고 있다. 안전한 운영체제에서는 사용자가 등급 즉, 자신의 보안등급과 보호범주를 설정하기 위해 권한 인증절차를 수행한다. 권한은 보안운영체제에서 강제적 접근 제어(Mandatory Access Control)의 기본이 되므로 그 보안에 중요성이 크다. 따라서, 권한 인증 절차의 보안이 부각되고 있다. 본 논문에서는 PKI 기반 전자서명 인증절차를 이용하여 신원 확인과 권한 인증을 한번에 수행할 수 있는 방법을 제시한다.

• 제어로봇시스템학회:학술대회논문집
• /
• 2001.10a
• /
• pp.113.3-113
• /
• 2001

In this paper, we have designed the VHDL module of DS/SS QPSK wireless modem processor for digital data communication. The spread spectrum method is used for modern processor, because this method guarantees good frequency efficiency and higher security. Also, it guarantees good performance in digital communication system under multi-path interferences. The differential encoder and decoder are used for simple circuit composition in the signal detection. For the synchronization of receiver, matched filter and power detector are used. And the IF modulation/demodulation of QPSK method is used in the digital level. The transmitter of VHDL modem processor consists of differential encoder, PN code generator, and QPSK ...

• Proceedings of the Korea Information Processing Society Conference
• /
• 2000.10a
• /
• pp.113-116
• /
• 2000

역할 기반의 접근제어 시스템은 응용에 따라 보호 객체들에 대한 접근을 역할들로 분류하고 이를 책임 있는 사용자에게 할당함으로써 개개의 사용자들에게 권한을 할당, 회수하는 전통적인 기법에 비해 단순하고 편리한 권한 관리를 제공한다. 다단계 보안 시스템은 각 시스템의 주체와 객체에게 보안 등급을 부여하고, 등급별로 분리된 정보의 보안을 유지하기 위해서 다중 보안 단계에서 정보를 처리하는 강제적 접근 제어를 제공한다. 본 논문에서는 MAC 기반의 데이터베이스 환경에서 최소 권한 정책을 반영하기 위하여 역할 기반의 접근 제어 기법을 적용한다. 따라서 같은 등급 혹은 그 이상의 등급을 가진 사용자라 할지라도 실제 데이터베이스 내에 저장된 데이터에 대한 권한 없는 접근, 고의적인 파괴 및 변경을 방지함으로써 실제 기업 환경에 적합한 다단계 역할기반 보안 모델을 제시한다.

• Journal of information and communication convergence engineering
• /
• v.8 no.4
• /
• pp.433-436
• /
• 2010

In this paper, we presented a ciphering method whose target data is any kind of digital bit-stream. It uses a chaotic system as the main encrypting tool, MISR (Multi-Input Signature Register), and shift-and-rotation function, all of which are exclusive-ORed with the plaintext. Also, it incorporates a cipher text feedback mode such that part of the previously ciphered data is fed back to encrypt the current data. The encryption block size and the amount of feedback data are different at each ciphering operation. Experimental results with the image/video date showed that this method has enough speed and encryption effect with negligible latency time. Thus, we are expecting it to have various application areas that need high speed stream ciphering with high security level.

• Proceedings of the KIEE Conference
• /
• 2000.07d
• /
• pp.2542-2544
• /
• 2000

In this paper, CAN(Controller Area Network)is used to solve the wire harness problem in the outside mirror of automobile which has a lot of functions in narrow space. If the number of wires is reduced, it has benefits of lower product cost and maintenance. CAN was originally developed by the German company Robert Bosch for use in the car industry to provide a cost-effective communications bus for in car electronics and as alternative to expensive and cumbersome wiring looms. CAN controller is a serial communication protocol which efficiently supports distributed real-time control with a very high level of security. The communication between master CAN controller and slave CAN controller is realized and controller's performance is tested by experiment.

• Nuclear Engineering and Technology
• /
• v.50 no.7
• /
• pp.1168-1172
• /
• 2018

This study went beyond making an indicator simply based on theoretical arguments, and explored a wide spectrum of different types of perceptions about energy safety to make a concept of energy safety for the Korean society. The energy safety schemata of people can be divided into three types. Type1 is concern about multi-level risks-responsibility-centric, type2 is concern about security and personal burden-expertise-centric, and type3 is concern about health and personal burden-responsibility-centric. Questions were designed on the basis of the characteristics, differences and commonalities of the three types of perceptions, explored through the Q methodology, and Koreans' perception of nuclear safety was examined. Based on the results of this research the following components of trust in nuclear safety were derived, risk perception, responsibility, honesty, expertise and procedural justification. The items for specifically evaluating them were developed, and factor analysis was conducted, and as a result, the validity of each item was proven. The components of the nuclear safety trust indicator do not exist independently, but influence each other continuously through interactions. For this reason, rather than focusing on any one of them, laws and systems must be improved first so that they can move together in one big frame.