• Journal of Internet Computing and Services
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• v.7 no.1
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• pp.17-30
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• 2006

With the wide acceptance of the Internet and the Web, volumes of information and related users have increased and companies have become to need security mechanisms to effectively protect important information for business activities and security problems have become increasingly difficult. This paper proposes a improved access control model for access control enforcement in enterprise environments through the integration of the temporal constraint character of the GT-RBAC model. sub-role hierarchies concept and PBDM(Permission Based Delegation Model). The proposed model. called Extended GT-RBAC(Extended Generalized Temporal Role Based Access Control) delegation Model. supports characteristics of GTRBAC model such as of temporal constraint, various time-constrained cardinality, control flow dependency and separation of duty constraints (SoDs). Also it supports conditional inheritance based on the degree of inheritance and business characteristics by using sub-roles hierarchies and supports permission based delegation, user to user delegation, role to role delegation, multi-step delegation and temporal delegation by using PBDM.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.638-641
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• 2016

UHD(Ultra High Definition) broadcasting is an attractive next-generation service of realistic broadcasting that enables you to feels like listening on the spot in ultra-high definition resolution. In addition, the test broadcasting run by UHD broadcasting agencies and UHDTV terminal launch could herald the full-scale UHD broadcasting era. However, in order that UHD broadcasting will be activated, the function of conditional access control and information protection through which we can on pay per view watch the programs of subscriber preference from the channels of various and subdivided genres is essential. To provide a technical foundation for these features and to achieve the UHD TV transition early, determining technology development & standardization strategy through the analysis of the key protection technologies is required In this paper, we propose standardization technologies which our country can lead and present a long-term driving directions by analyzing UHD broadcasting technology & test broadcasting trends and content protection technology & standardization trends.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.1
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• pp.175-186
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• 1996

An optimal channel input-traffic control (OCIC) policy is proposed for slotted frequency-hopped spread-spectrum multiple access communication systems. When the number of channel input packets is set to the optimal number, the conditional throughput for the OCIC policy is analyzed. The state transition probability is derived, the steady state performance is analyzed, and the mean pracket delay is obtained. It is shown that the mean packet delay decreases considerably when the priority of transmission is given to backlogged users. The smaller is the number of requency slots, the larger are the differences between the preformance of the OCIC policy and that of the other policies.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.8 no.2
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• pp.64-71
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• 2009

In this paper, This thesis is cell phone for make CAS service be for hand joining broadcasting Create a way CAS Chip. PerSam issue card inside use Seed Key and algorithm make CID Key and record CAS Chip. PerSam member Card inside use Seed Key and algorithm make Subscriber Key after include Subscriber. Key CAS Chip for record CID Key register EMM. make CAS CHIP in accordance with issue CAS Chip. broadcast service entry be for hand treatment so make low bandwidth for joining massage and make increase a member.

• Journal of KIISE:Information Networking
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• v.36 no.6
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• pp.471-480
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• 2009

One of the principal impediments to the achievement of a scalable access control for a large number of subscribers in a public broadcast is to distribute key update messages reliably to all stateless receivers. However, in a public broadcast, the rekeying messages can be dropped or compromised during the transmission over an insecure broadcast channel, or transmitted to the receivers while it was off-line. In this study, we propose a novel group key management scheme that features a mechanism that allows the legitimate receivers to recover the current group key even if they lose key update messages for long-term sessions using short hint messages and member computation. The performance analysis result shows that the proposed scheme has advantages of the scalable and efficient rekeying compared with the previous reliable group key distribution schemes. The proposed key management scheme targets a conditional access system in a media broadcast where there is no feedback channel from receivers to the broadcasting station.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.05a
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• pp.929-932
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• 2006

본 논문에서는 암호화된 Scalable Video Coding (SVC) 비트스트림에서의 조건적 접근제어을 위한 키 관리 기법을 제안한다. 스케일러블 비디오 코딩 기술은 한번 인코딩 후 비트스트림 추출을 통해 다양한 확장성(scalabbility)을 가지는 비디오를 생성 할 수 있는 기술로 확장하는 단위마다 다른 키로 암호화 하여 조건적 접근제어를 구성 할 수 있다. 그러나 기존의 조건적 접근제어 기술은 암호화 시 복수의 키가 필요하며 이는 키의 관리와 분배에 어려움을 준다. 이러한 문제를 해결하기 위해 본 논문에서는 기존의 스케일러블 코딩기법에서 조건적 접근제어를 위한 키 관리기법을 살펴보고 SVC 의 확장 구조에 맞는 키 관리 기법을 제안한다. 제안한 방법은 SVC 를 이용한 스트리밍 테스트베드에서 구현되어, 조건적 접근제어를 위한 키 관리기능의 유용성을 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.207-209
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• 1996

The software of the midclass commuter flight simulation is running on multiprocessor/multitasking environments The software is consist of tasks which are periodically alive at a given interval. Each task communicates via shared memory. The data shared by tasks is divided by several block. Only one task, called producer, can produce data for a data block but several tasks, called consumers, can read data from the data block. Double buffer and conditional flag are used to implement a mutual exclusion which prevents the producer and consumers from accessing the same data block simultaneously.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.667-668
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• 2009

IPTV 시스템에서 서비스 제공자는 제한수신시스템(CAS, Conditional Access System)을 통해 미디어 콘텐츠의 안전한 전송을 제공한다. Scramble Function의 Pseudo-random sequence 생성 초기화 단계에서 사용하는 CW(Control Word)를 허가된 사용자만 획득하게 함으로써 데이터를 보호한다. 적합한 사용자 측에서는 스마트카드를 통해 획득한 CW를 셋톱박스에 전송하고, 셋톱박스는 CW를 이용해 암호화된 데이터로부터 원본의 미디어 콘텐츠를 획득한다. 이 때, CW가 그대로 셋톱박스에게 전송되기 때문에 비인가된 사용자가 공격을 통해 CW를 획득할 수 있어서 암호화된 전송이 요구된다. 이본 논문에서는 스마트카드와 셋톱박스 사이의 암호화 통신을 위해 기존의 방법보다 경량화된 상호인증 및 키 동의 프로토콜을 제안한다.

• Journal of the Korea Society of Computer and Information
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• v.15 no.7
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• pp.57-66
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• 2010

Due to the advancement of IPTV technologies, open IPTV services are a step closer to becoming reality. In such service environment, users are able to enjoy IPTV services using a variety of devices available at their home domain. However, it is impossible to get such flexible services at their convenience unless each of devices is individually connected to Set-Top-Box (STB) because of Conditional Access System (CAS) or service providers otherwise allow STB to freely distribute decoded contents to every user devices attached to STB. In this paper, we propose a key management scheme for securely distributing contents from STB to multiple user devices at home domain. The proposed scheme also makes the service providers be able to control the access rights to each of user devices without installing individual STBs. It is achieved by computationally dividing a private key of RSA signature scheme into three parts and thus makes possible to distribute the contents scrambled through a underlying CAS mechanism without re-encrypting them that the existing scheme should employ. It improves significantly computation and communication complexities, maintaining it as secure as the existing schemes. Additionally, it prevents misbehaving users from illegally distributing the contents from STB to their devices available at home domain.

• The KIPS Transactions:PartC
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• v.16C no.1
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• pp.21-26
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• 2009

Presently, the demand for IPTV, to satisfy a variety of goals, is exploding. IPTV is coming into the spotlight as a killer application in upcoming IP convergence networks such as triple play which is the delivery of voice, internet, and video service to a subscriber. IPTV utilizes CAS, which controls the subscriber access to content for a profit. Although the current CAS scheme provides access control via subscriber authentication, there is no authentication scheme for the content transmitted from service providers. Thus, there is a vulnerability of security, through which an adversary can forge content between the service provider and subscribers and distribute malicious content to subscribers. In this paper, based on a hash tree scheme, we proposed efficient and strong source authentication protocols which remove the vulnerability of the current IPTV system. We also evaluate our protocol from a view of IPTV requirements.