• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.116-118
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• 2011

최근 유료 방송 서비스를 위한 제한수신 시스템의 적용에 있어 지적되었던 여러 문제들을 해결할 수 있는 DCAS(Downloadable Conditional Access System) 기술이 소개되었다. 또한, OpenCable과 DCAS를 기반으로 국내 디지털 케이블 방송 시스템을 위한 교환가능형 제한수신 시스템(eXchangeable CAS: XCAS) 표준이 재정되었다. 본 논문에서는 DCAS와 국내 XCAS 표준 규격을 기반으로 개발된 다운로드형 제한수신 시스템을 소개하고, 개발된 시스템의 성능 검증 결과를 제시하여 상용 유료방송 시스템에 적용하는 방안에 대해 논하고자 한다.

• Broadcasting and Media Magazine
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• v.13 no.4
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• pp.54-64
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• 2008

• The KIPS Transactions:PartC
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• v.17C no.5
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• pp.407-414
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• 2010

A condition access system (CAS) refers to a hardware-based system that allows only authenticated users to have access to contents. The CAS has many disadvantages found in that in the replacement of multiple service operator (MSO) a set-top box should be also changed and the smart-card often causes malfunction. To deal with the problems, exchangeable CAS (XCAS) was developed in 2009. However the standards or evaluation schemes for XCAS are absent. Existing evaluation schemes are not appropriate for evaluating XCAS due to the evaluation standard, the evaluation cost and efficiencies. Therefore, a specific scheme that can evaluate the security and suitability of exchangeable conditional access systems has been requested. In this paper, we propose an appropriate evaluation scheme for XCAS. The evaluation scheme includes an evaluation purpose and four components to evaluate the evaluation target, the evaluation process, the evaluation subject, and the evaluation cost involved.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.11a
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• pp.196-199
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• 2013

제한수신시스템(Conditional Access System, CAS)은 사용자의 조건에 따라 방송에 대한 접근을 제어하는 시스템으로 유료 방송 시스템에서 인가된 사용자만이 해당 프로그램에 접근할 수 있도록 하는 콘텐츠 보안 기술이다. 최근에는 기존의 하드 웨어 기반 CAS가 가지는 이기종 기기간 호환성과 다른 서비스와의 연동 등의 문제를 해결하고자 CAS 모듈을 소프트웨어로 구현하여 네트워크를 통해 설치하는 교환 가능형 제한수신시스템(eXchangeable CAS, 이하 XCAS) 방식을 도입하여 활발하게 서비스를 제공하고 있다. XCAS는 기존 CableCard방식이 가지는 CAS의 보안성과 분리교환 원칙을 유지하면서도 다양한 단말에 쉽게 설치하여 서비스가 가능하다는 점에서 큰 장점을 가지고 있지만, 방송수신만을 목적으로 하는 DTV(Digtal Television)에 대해 적용하기가 어렵다는 문제점이 존재하였다. 본 논문에서는 케이블방송환경에서 DTV를 통한 유료방송서 비스 제공을 위한 DTV 인증 및 XCAS 서비스에 필요한 SM(Secure Module) 모듈을 다운로드하기 위한 기법을 제안한다.

• The Journal of the Korea Contents Association
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• v.10 no.5
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• pp.37-44
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• 2010

The mobility is one of the most important factor for mobile IPTV. However, mobility is highly vulnerable to eavesdropping and unauthorized access. Generally mobility of mobile services is based on handover techniques. But we showed that mobile IPTV must use other techniques to confirm mobility. In this paper, we analyzed security of wibro mobile IPTV from the viewpoint of mobility. We considered DCAS host must include new addresses of mobile devices. We analyzed total number of authentication for the proposed method. So we showed that proposed method was more efficient than wibro-mobile IPTV. We compared the security of our proposal to the security requirements of TTA.

• The KIPS Transactions:PartC
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• v.17C no.4
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• pp.347-360
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• 2010

A condition access system (CAS) refers to a hardware-based system that allows only authenticated users to have access to contents. The CAS has many disadvantages found in that in the replacement of multiple service operator (MSO) a set-top box should be also changed and the smart-card often causes malfunction. To deal with the problems, exchangeable CAS (XCAS) was developed in 2009. However, in the XCAS, no method to authenticate a proper set-top box has been put forward. In this paper, we propose a novel program for set-top authentication in the XCAS. Additionally, we offer a format of certificate of authentication, and procedures of issuing the certificate for broadcasting services suitable for the XCAS. The technical method of authentication a set-top box that will be discussed is of high efficiency since in the MSO it requires only two subjects to communicate during the authentication in the MSO.

• Journal of the Korea Society of Computer and Information
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• v.15 no.11
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• pp.57-66
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• 2010

CAS Client personalization means to issue CAS ID or Key for CAS service, which is Core Technology for CAS operation. Protocol A.1 on TTA.KR-07.0079 XCAS, stores CAS Client personalization data from CAS server in XCAS server, and transmits the personalization data by request of XCAS HOST for CAS Client personalization. However, this may increase Network Traffic and CAS Client image management in XCAS server. In this thesis, to complement this, CAS Client personalization is executed on CAS Server by separating CAS service field. Therefore this can distribute Image management and Network Traffic of XCAS server.