• ETRI Journal
• /
• 제32권5호
• /
• pp.704-712
• /
• 2010

Authentication is an important service in wireless sensor networks (WSNs) for an unattended environment. Recently, Das proposed a hash-based authentication protocol for WSNs, which provides more security against the masquerade, stolen-verifier, replay, and guessing attacks and avoids the threat which comes with having many logged-in users with the same login-id. In this paper, we point out one security weakness of Das' protocol in mutual authentication for WSN's preservation between users, gateway-node, and sensor nodes. To remedy the problem, this paper provides a secrecy improvement over Das' protocol to ensure that a legal user can exercise a WSN in an insecure environment. Furthermore, by presenting the comparisons of security, computation and communication costs, and performances with the related protocols, the proposed protocol is shown to be suitable for higher security WSNs.

• 한국통신학회논문지
• /
• 제36권3B호
• /
• pp.214-219
• /
• 2011

최근 IMS(IP Multimedia Subsystem)는 통신 사업자에게 멀티미디어 서비스 제공을 위한 제어망으로 사용되고 있다. 이러한 IMS는 기능에 따라 다양한 노드들로 구성되는데 이러한 노드의 상태(성능, 고장 등)에 따라 적절한 라우팅을 제공하기위한 동적라우팅 알고리즘이 필요하다. 따라서 본 논문에서는 네트워크 관리 기능을 바탕으로 IMS에서 호 및 세션 처리에 관여하는 CSCF(Call Session Control Function)의 효과적인 동적 라우팅을 위한 SIP 라우팅 알고리즘을 제안 및 구현한다.

• ETRI Journal
• /
• 제45권6호
• /
• pp.1090-1102
• /
• 2023

Authenticated multiple key agreement (AMKA) protocols provide participants with multiple session keys after one round of authentication. Many schemes use Diffie-Hellman or authenticated key agreement schemes that rely on hard integer factorizations that are vulnerable to quantum algorithms. Lattice cryptography provides quantum resistance to authenticated key agreement protocols, but the certificate always incurs excessive public key infrastructure management overhead. Thus, a lightweight lattice-based secure system is needed that removes this overhead. To answer this need, we provide a two-party lattice- and identity-based AMKA scheme based on bilateral short integer or computational bilateral inhomogeneous small integer solutions, and we provide a security proof based on the random oracle model. Compared with existing AMKA protocols, our new protocol has higher efficiency and stronger security.

• International Journal of Internet, Broadcasting and Communication
• /
• 제8권3호
• /
• pp.41-49
• /
• 2016

Recently, many biometrics-based user authentication schemes for telecare medicine information systems (TMIS) have been proposed to improve the security problems in user authentication system. In 2014, Mishra et al. proposed an improvement of Awasthi-Srivastava's biometric based authentication for TMIS which is secure against the various attacks and provide mutual authentication, efficient password change. In this paper, we discuss the security of Mishra et al.'s authentication scheme, and we have shown that Mishra et al.'s authentication scheme is still insecure against the various attacks. Also, we proposed the improved scheme to remove these security problems of Mishra et al.'s authentication scheme, even if the secret information stored in the smart card is revealed. As a result, we can see that the improved biometric based authentication scheme is secure against the insider attack, the password guessing attack, the user impersonation attack, the server masquerading attack and provides mutual authentication between the user and the telecare system.

• 한국감성과학회:학술대회논문집
• /
• 한국감성과학회 1998년도 춘계학술발표 논문집
• /
• pp.304-308
• /
• 1998

Technical advances in computer networks and the Internet bring a new communication era and provide effective solutions for cooperative works and research. These technological advances introduced the concept of cyberspace that many people involve reseach and a project at different locations at the same time. In this paper, we present a fast and effective interaction protocol that is aeapted to the COLAB(COIIaborative LABoratory) Systems which use a high-speed ATM Network. The CCOLAB systems is developed for researchers those who are doing a large project on the collaborative research environment. The interaction protocol that we developed supports multi-session and multi-channel on the TCP/IP Network and provides more flexible solution to control multimedia data on the network.

• 치위생과학회지
• /
• 제15권2호
• /
• pp.220-225
• /
• 2015

본 연구에서는 국내에서 권장하고 있는 회전법이 실천 용이하고 치면세균막 제거에 효과적인지 다른 칫솔질 방법과 비교해 보고, 집단칫솔질교육 후 시간흐름에 따른 효과추이를 확인하고자 임의 추출한 20대 대학생을 대상으로 O'leary 지수와 PHP 지수를 구하고 칫솔질 수행도를 조사하였다. 분석은 STATA 11.0을 이용하였다. 회전법과 바스법, 와타나베법의 칫솔질 방법에 따라 O'leary 지수와 PHP 지수 및 칫솔질 수행도가 차이가 있는지에 대해 조사하기 위해 1차부터 3차까지 평균을 비교한 결과 차이가 없었다. 칫솔질 교육 전인 1차, 칫솔질 교육 2주 후인 2차, 칫솔질 교육 4주 후인 3차의 O'leary 지수, PHP 지수 및 칫솔질 수행도의 차이를 확인하기 위해 비모수 표본자료에 사용하는 Kruskal-Wallis test를 수행한 결과 O'leary 지수의 경우 칫솔질 교육 전 측정 시 가장 낮은 점수를 기록하였고, 2차시기 측정치가 가장 높게 나타났다(p=0.0001). PHP 지수는 1차시기 가장 높게 나타났고, 2차시기 감소하였다가 3차시기 다시 증가하는 것으로 나타났다(p=0.0001). 칫솔질 수행도 역시 PHP 지수와 유사한 경향을 보였다(p=0.0001). 이상의 결과로 회전법이 모든 사람에게 획일적으로 권장할 만한 방법인지 좀 더 다각적인 고찰이 필요하고, 칫솔질 교육효과는 시간이 지나면서 감소되므로 지속적인 교육이 실행될 수 있도록 제도적 장치가 마련되어야 함을 알 수 있었다.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
• /
• pp.91-94
• /
• 2004

Ubiquitous sensor network is to manage and collect information autonomously by communicating user around device. Security requirements in Ubiquitous based on sensor network are as follows: a location of sensor, a restriction of performance by low electric power, communication by broadcasting, etc. We propose new mutual authentication protocol using a low power of sensor node. This protocol solved a low power problem by reducing calculation overload of sensor node using two steps, RM(Register Manager) and AM(Authentication Manager). Many operations performing the sensor node itself have a big overload in low power node. Our protocol reduces the operation number from sensor node. Also it is mutual authentication protocol in Ubiquitous network, which satisfies mutual authentication, session key establishment, user and device authentication, MITM attack, confidentiality, integrity, and is safe the security enemy with solving low electric power problem.

• ETRI Journal
• /
• 제28권6호
• /
• pp.709-720
• /
• 2006

In this paper, we suggest a simple and efficient multiple-forwarder-based file distribution method which can work with a tree-based application layer multicast. Existing multiple-forwarder approaches require high control overhead. The proposed method exploits the assumption that receivers join a session at different times. In tree-based application layer multicast, a set of data packets is delivered from its parent after a receiver has joined but before the next receiver joins without overlapping that of other receivers. The proposed method selects forwarders from among the preceding receivers and the forwarder forwards data packets from the non-overlapping data packet set. Three variations of forwarder selection algorithms are proposed. The impact of the proposed algorithms is evaluated using numerical analysis. A performance evaluation using PlanetLab, a global area overlay testbed, shows that the proposed method enhances throughput while maintaining the data packet duplication ratio and control overhead significantly lower than the existing method, Bullet.

• Journal of Information Processing Systems
• /
• 제5권1호
• /
• pp.19-24
• /
• 2009

Many researchers have developed frameworks that are capable of handling context information and can be adapted and used by any Web service. However, no research involving the systematic analysis of existing frameworks has yet been conducted. This paper examines the Context Framework, an example of existing frameworks, using a Petri net, and analyzes its advantages and disadvantages. Then, a Petri net model - with its disadvantages removed - is introduced, and a new framework is presented on the basis of that model. The proposed PAWS (Privacy Aware Web Services) framework has a expendability for context management and communicates flexible context information for every session. The proposed framework can solve overhead problems of context in SOAP messages. It also protects user privacy according to user preferences.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
• /
• pp.227-230
• /
• 2005

The concepts of flexible displays and plastic electronics have become some of the most talked about new product opportunities for direct view flat panel displays in recent years. The potential advantages are frequently cited, but the achievement of commercially viable products will require many significant technological innovations in new materials and manufacturing technology. This paper will provide a very broad overview of the rationale for developing flexible displays, the market drivers, the applicable display technologies, the major hurdles that must be overcome and the required evolution of new manufacturing technologies that are essential for successful commercialization. This is intended to provide the outline and context for the series of presentations on specific aspects in each of these topics that will be delivered and discussed at the Plastic Electronics Special Session of the 2005 IMID conference.