• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.1
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• pp.202-210
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• 2018

The modern battlefield is being developed as a network-centric warfare where priority is given to rapid status grasp and power deployment through scientification and modernization. Therefore, tactical data link has been continuously improving the network speed, and recently, security technology is required for wireless communication with the UAV and various devices for reconnaissance. In addition, the future information warfare will utilize advanced IT technology positively. Efforts are needed to integrate various systems and networks. However, these efforts are meaningful only when they can assume sufficient security in a newly changing information and communication environment. In this paper, we propose a new cryptographic synchronization for link encryption suitable for tactical data links. The proposed cryptographic synchronization is useful for T4 UAV link encryption, and it is also adaptable for lower BER, then we analyze the performances analysis of that.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.12
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• pp.2891-2898
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• 2013

CCSDS Standard is widely used in international space telecommunication area. In this standard, Encryption is realized using a unique hierarchical encryption protocol and satisfied security requirements of communication channels. For synchronization, encryption sync is attached in the beginning of encrypted data. But exceptional case(timing jittering, abnormal system shutdown, etc.) is occurred, receiving equipment cannot decrypt received data. In this paper, we propose a SES Alarmed link encryption synchronization method for sending warning signal to the transmitter when some problems have been occurred during the transmission and we also suggest optimum conditions for SES Alarm signal through performance analysis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.1
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• pp.211-220
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• 2018

The standard data link layer encryption provided by CCSDS has a structure that encodes HDLC frame into it using an AES algorithm. However, CCSDS is standard method has a structure in which the receiving side cannot request a re-activation when noise interference occurs over an unstable channel. SES Alarmed has a structure that enables the receiving side to additionally detect errors and perform re-activation requests in an operational structure similar to that of link encryption in CCSDS. The SES Alarmed related paper was intended to identify the optimum range of thresholds and identify data corruption due to channel noise. In this paper, the focus was on reducing the re-activation process if the HDLC frame, excluding the password Sync code, consistently exceeds any threshold levels. The HDLC frame order was changed and the results of using SES Alarmed were proposed and compared.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.10
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• pp.89-96
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• 2003

In this paper, a CCSDS(Consultative Committee for Space Data Systems) telecommand(TC) decryptor for the security of geostationary communications satellite was implemented. For the confidentiality of CCSDS TC datalink security, Option-A which implements the security services below the transfer sublayer was selected. Also CFB(Cipher Feedback) operation mode of DES(Data Encryption Standard) was used for the encryption of 56-bit data bits in 64-bit codeblock. To verify Decryptor function, the DES CFB logic implemented on A54SX32 FPGA(Field Programmable Gate Array) was integrated with interface and control logics in a PCB(Printed Circuit Board). Using a function test PC, the encrypted codeblocks were generated, transferred into the decryptor, decrypted, and the decrypted codeblocks were transmitted to the function test PC, and then compared with the source codeblocks. Through LED(Light Emitting Diode) ON operation by driving the relay related to Op-code decoded and the comparison between the codeblock output waveforms measured and those simulated, the telecommand decryptor function was verified.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.8 no.2
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• pp.67-80
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• 1998

논문에서는 프레임릴레이 프로토콜을 사용하는 암호 통신 시스템에 적합한 키 스트림 동기 방식을 제안하였다. 제안된 주소영역의 확장 비트를 이용한 키 스트림 동기 방식은 단위 측정 시간 동안 측정된 프레임릴레이 프로토콜의 주소영역의 확장 비트 정보와 플래그 패턴의 수신률을 이용하여 문턱값보다 적은 경우에 동기 신호와 세션 키를 전송하므로써 종래의 주기적인 동기 방식에서 전송 효율성 저하와 주기적인 상이한 세션 키 발생, 다음 주김까지 동기 이탈 상태로 인한 오류 확산 등의 단점을 해결하였다. 제안된 알고리즘을 데이터 링크 계층의 처리기능을 최소화하여 패킷 망의 고속화가 가능하도록 설계된 프레임릴레이 프로토콜에서 서비스되는 동기식 스트림 암호 통신 시스템에 적용하여 slip rate $10^{-7}$의 환경에서 주기가 Isec인 주기적인 동기 방식에서 요구되는 9.6*10/ sup 6/비트에 비해 6.4*$10^{5}$비트가 소요됨으로써 전송율 측면에서의 성능 향상과 오복호율과 오복호율과 오복호 데이터 비트 측면에서 성능 향상을 얻었다.다.

• Proceedings of the KAIS Fall Conference
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• 2007.05a
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• pp.203-207
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• 2007

NEMO 기본 지원 (NEMO-BS, NEMO Basic Support) 프로토콜에서 MNN(Mobile Network Node)가 CN(Correspondent Node) 과 통신을 하기 위해서는 항상 MR(Mobile Router)과 HA(Home Agent) 사이의 양방향 터널을 이용해야 한다. 그러나 NEMO-BS 방식은 노드 간 데이터 전송 지연과 부분 구간에 대한 공격 가능성이 존재한다. 따라서 본 논문에서는 NEMO를 위한 인증된 경로 최적화(ATRO) 프로토콜을 제안한다. MR은 홈 링크로부터 멀어졌다고 판단되면 MNN으로부터 위임 권한을 얻기 위해 권한 위임 프로토콜을 수행한다. 그런 후에 MR과 CN은 공개키 암호 방식을 이용하여 자신의 의탁주소(CoA, Care-of Address)를 MNN의 홈 주소(HoA, Home-of Address)와 매핑하기 위한 등록 과정을 수행한다. 이때 각 노드의 주소 소유권 증명을 위해 암호학적으로 생성한 주소(CGA, Cryptographically Generated Address)를 이용한다. 성능분석에서는 구간별 안전성과 종단간 패킷 전송 지연 시간을 통해 프로토콜을 분석한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.9
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• pp.1916-1932
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• 1997

The synchronous stream cipher which require absoulte clock synchronization has the problem of synchronization loss by cycle slip. Synchronization loss makes the state which sender and receiver can't communicate with each other and it may break the receiving system. To lessen the risk, we usually use a continuous resynchronization method which achieve resynchronization at fixed timesteps by inserting synchronization pattern and session key. While we can get resynchronization effectively by continuous resynchroniation, there are some problems. In this paper, we proposed an adaptive resynchronization algorithm for cipher system using HDLC protocol. It is able to solve the problem of the continuous resynchronization. The proposed adaptive algorithm make resynchronization only in the case that the resynchronization is occurred by analyzing the address field of HDLC. It measures the receiving rate of theaddress field in the decision duration. Because it make resynchronization only when the receiving rate is greateer than the threshold value, it is able to solve the problems of continuous resynchronization method. When the proposed adaptive algorithm is applied to the synchronous stream cipher system in packet netork, it has addvance the result in R_e and D_e.