• 한국컴퓨터정보학회지
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• 제11권1호
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• pp.9-17
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• 2003

우리나라에서도 정보통신부는 국가 및 공공기관의 전산망 품질수준을 제고하고 효율적인 정보시스템 구축을 지원하기 위해 공공부문 정보화사업에 대한 감리 제도의 활성화, 정보시스템 감리 자격제 도입, 민간 감리 기관의 육성 등을 주요 내용으로 하는 $\ulcorner$정보시스템 감리 제도 도입계획$\lrcorner$ 을 마련해 본격 시행에 들어가기로 했다. 정통부가 이번에 정보시스템 감리제도를 크게 강화하기로 한 것은 최근 들어 국가 및 공공기관을 중심으로 정보시스템 분야의 감리 수요가 폭발적으로 증가하고 있음에도 불구하고 한국전산원에 감리 업무가 집중되고 있어 공공부문의 감리 수요를 충족시키기 힘든 데다 국가정보화 사업에 대한 감리 제도의 도입 필요성이 점차 높아지고 있기 때문으로 풀이된다. 정통부는 감리제도를 활성화하기 위해 공공부문 정보시스템 감리를 정보화사업과 연계해 제도화한다는 방침을 세우고 공공부문 정보화사업에 대한 감리를 주관기관의 판단에 일임하되 정보화 추진위원회가 정한 국가적인 중요 사업에 대해선 감리를 의무화하기로 했다. 이에 대해 내. 외부 감사중 내부감사에 대해 그 내용을 파악해 보자는 데 그 목적이 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권8호
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• pp.3641-3655
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• 2016

Wireless sensor networks (WSNs) provide a promising approach to monitor the physical environments, to prolong the network lifetime by exploiting the mutual correlation among sensor readings has become a research focus. In this paper, we design a hierarchical network framework which guarantees layered-compression. Meanwhile, a data sorting-based adaptive spatial compression scheme (DS-ASCS) is proposed to explore the spatial correlation among signals. The proposed scheme reduces the amount of data transmissions and alleviates the network congestion. It also obtains high compression performance by sorting original sensor readings and selectively discarding the small coefficients in transformed matrix. Moreover, the compression ratio of this scheme varies according to the correlation among signals and the value of adaptive threshold, so the proposed scheme is adaptive to various deploying environments. Finally, the simulation results show that the energy of sorted data is more concentrated than the unsorted data, and the proposed scheme achieves higher reconstruction precision and compression ratio as compared with other spatial compression schemes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권10호
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• pp.3557-3571
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• 2014

We develop a secret key generation scheme using phase estimation in ultra-wideband (UWB) wireless fading channels. Based on the reciprocity theorem, two terminals extract the phase of the channel as a common random source to generate secret bits. Moreover, we study the secret key rate by a pair of nodes observing correlated sources and communicating to achieve secret key agreement over public communication channels. As our main results, we establish a more practical upper bound from Cramer-Rao bound (CRB) and compare it with a universally theoretical upper bound on the shared maximum key rate from mutual information of correlated random sources. Derivation and numerical examples are presented to demonstrate the bound. Simulation studies are also provided to validate feasibility and efficiency of the proposed scheme.

• Journal of Communications and Networks
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• 제12권6호
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• pp.592-599
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• 2010

In recent years, significant improvements have been made to the techniques used for analyzing satellite communication and attacking satellite systems. In 2003, a research team at Los Alamos National Laboratory, USA, demonstrated the ease with which civilian global positioning system (GPS) spoofing attacks can be implemented. They fed fake signals to the GPS receiver so that it operates as though it were located at a position different from its actual location. Moreover, Galileo in-orbit validation element A and Compass-M1 civilian codes in all available frequency bands were decoded in 2007 and 2009. These events indicate that cryptography should be used in addition to the coding technique for secure and authenticated satellite communication. In this study, we address this issue by using an authenticated key-exchange protocol to build a secure and authenticated communication channel for satellite communication. Our protocol uses identity-based cryptography. We also prove the security of our protocol in the extended Canetti-Krawczyk model, which is the strongest security model for authenticated key-exchange protocols, under the random oracle assumption and computational Diffie-Hellman assumption. In addition, our protocol helps achieve high efficiency in both communication and computation and thus improve security in satellite communication.

• 기술혁신학회지
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• 제1권1호
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• pp.23-36
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• 1998

The 1995 Informatization Promotion Act was passed to advance the national quality of life and to develop national economy by promoting informatization, forming the ground of telecommunication industry, and realizing the advancement of telecommunication infrastructure. This article was written to review whether this act's purpose was being achieved by Korean government. Even if Korean informatization policy implemetation structure is strongly centralized around the Ministry of Information and Communication, Information policies are formulated and implemented among agencies. To explain this phenomenon, I suggested the following factors : (1) The Korean government's lack of informatization experiences, (2) The political abuse of information policy, (3) the conceptual rigidity on the structure of information superhighway, (4) the absence of the basic principles for electronic government, (5) the uniformed regional informatization.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권4호
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• pp.1795-1811
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• 2019

In order to achieve rapid and accurate detection of vehicle objects in complex traffic conditions, we propose a novel vehicle detection method. Firstly, more contextual and small-object vehicle information can be obtained by our Joint Feature Network (JFN). Secondly, our Evolved Region Proposal Network (EPRN) generates initial anchor boxes by adding an improved version of the region proposal network in this network, and at the same time filters out a large number of false vehicle boxes by soft-Non Maximum Suppression (NMS). Then, our Mask Network (MaskN) generates an example that includes the vehicle occlusion, the generator and discriminator can learn from each other in order to further improve the vehicle object detection capability. Finally, these candidate vehicle detection boxes are optimized to obtain the final vehicle detection boxes by the Fine-Tuning Network(FTN). Through the evaluation experiment on the DETRAC benchmark dataset, we find that in terms of mAP, our method exceeds Faster-RCNN by 11.15%, YOLO by 11.88%, and EB by 1.64%. Besides, our algorithm also has achieved top2 comaring with MS-CNN, YOLO-v3, RefineNet, RetinaNet, Faster-rcnn, DSSD and YOLO-v2 of vehicle category in KITTI dataset.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권5호
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• pp.2375-2393
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• 2016

Key agreement is paramount in secure wireless communications. A promising approach to address key agreement schemes is to extract secure keys from channel characteristics. However, because channels lack randomness, it is difficult for wireless networks with stationary communicating terminals to generate robust keys. In this paper, we propose a Robust Secure Key Agreement (RSKA) scheme from Received Signal Strength (RSS) in stationary wireless networks. In order to mitigate the asymmetry in RSS measurements for communicating parties, the sender and receiver normalize RSS measurements and quantize them into q-bit sequences. They then reshape bit sequences into new l-bit sequences. These bit sequences work as key sources. Rather than extracting the key from the key sources directly, the sender randomly generates a bit sequence as a key and hides it in a promise. This is created from a polynomial constructed on the sender's key source and key. The receiver recovers the key by reconstructing a polynomial from its key source and the promise. Our analysis shows that the shared key generated by our proposed RSKA scheme has features of high randomness and a high bit rate compared to traditional RSS-based key agreement schemes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권6호
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• pp.2492-2512
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• 2018

Multicast communication can effectively reduce network resources consumption in contrast with unicast. With the advent of SDN, current researches on multicast traffic are mainly conducted in the SDN scenario, thus to mitigate the problems of IP multicast such as the unavoidable difficulty in traffic engineering and high security risk. However, migration to SDN cannot be achieved in one step, hybrid SDN emerges as a transitional networking form for ISP network. In hybrid SDN, for acquiring similar TE and security performance as in SDN multicast, we redirect every multicast traffic to an appropriate SDN node before reaching the destinations of the multicast group, thus to build up a core-based multicast tree substantially which is first introduced in CBT. Based on the core SDN node, it is possible to realize dynamic control over the routing paths to benefit traffic engineering (TE), while multicast traffic manageability can also be obtained, e.g., access control and middlebox-supported network services. On top of that, multiple core-based multicast trees are constructed for each multicast group by fully taking advantage of the routing flexibility of SDN nodes, in order to further enhance the TE performance. The multicast routing and splitting (MRS) algorithm is proposed whereby we jointly and efficiently determine an appropriate core SDN node for each group, as well as optimizing the traffic splitting fractions for the corresponding multiple core-based trees to minimize the maximum link utilization. We conduct simulations with different SDN deployment rate in real network topologies. The results indicate that, when 40% of the SDN switches are deployed in HSDN as well as calculating 2 trees for each group, HSDN multicast adopting MRS algorithm can obtain a comparable TE performance to SDN multicast.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권1호
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• pp.1-19
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• 2015

With the recent popularity of smart terminals, the demand for high-data-rate transmission is growing rapidly, which brings a new challenge for the traditional cellular networks. Both device-to-device (D2D) communication and small cells are effective to improve the transmission efficiency of local communication. In this paper, we apply D2D communication into a small cell network system (SNets) and study about the optimization problem of resource allocation for D2D communication. The optimization problem includes system scheduling and resource allocation, which is exponentially complex and the optimal solution is infeasible to achieve. Therefore, in this paper, the optimization problem is decomposed into several smaller problems and a hierarchical scheme is proposed to obtain the solution. The proposed hierarchical scheme consists of three steps: D2D communication groups formation, the estimation of sub-channels needed by each D2D communication group and specific resource allocation. From numerical simulation results, we find that the proposed resource allocation scheme is effective in improving the spectral efficiency and reducing the outage probability of D2D communication.

• 한국통신학회:학술대회논문집
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• 한국통신학회 2004년도 추계종합학술대회 논문 초록집
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• pp.350-350
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• 2004