• 한국컴퓨터산업학회논문지
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• 제9권2호
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• pp.93-98
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• 2008

본 논문은 Cellular Automata 기초로 형성된 stream cipher에 대해 원리를 분석하였다. 원래 Cellular Automata는 State, Neighborhood, Transition Rules이라는 단순한 특징을 가지고 복잡하고 다양한 원리를 구현할 수 있다. 즉 Cellular Automata는 transition nile를 이용하여 암호화를 원활하게 처리할 수 있다는 것을 암시하고 있다. 따라서 본 논문에서는 Cellular Automata의 transition rule 30 적용으로 binary pad(key stream)을 생성하고, 암호 분류 중 symmetric key encryption 방식의 stream cipher를 이용하여 encryption 및 decryption의 능력을 실험하였다.

• International Journal of Computer Science & Network Security
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• 제23권1호
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• pp.164-168
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• 2023

As our community has become increasingly dependent on technology, security has become a bigger concern, which makes it more important and challenging than ever. security can be enhanced with encryption as described in this paper by combining RC6 symmetric cryptographic algorithms with RSA asymmetric algorithms, as well as the Vigenère cipher, to help manage weaknesses of RC6 algorithms by utilizing the speed, security, and effectiveness of asymmetric algorithms with the effectiveness of symmetric algorithm items as well as introducing classical algorithms, which add additional confusion to the decryption process. An analysis of the proposed encryption speed and throughput has been conducted in comparison to a variety of well-known algorithms to demonstrate the effectiveness of each algorithm.

• Journal of applied mathematics & informatics
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• 제8권3호
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• pp.943-957
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• 2001

In this paper, we propose an efficient encryption algorithm, without exchanging session keys of a symmetric cryptosystem. The proposed scheme, called as the FAKE(Fast Asymmetric Key Encryption), first scrambles an entire input message and then encrypts small parts of the scrambled message using an asymmetric key encryption scheme. We use the all-or-nothing transform based on the hash function as a scrambling function, which was proposed by Shin, et al. Furthermore, the proposed scheme can additionally provide a digital signature service with only small overhead.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.341-344
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• 2002

The importance of protection for information is increasing by the rapid development of information communication and network. Asymmetric crypto-system is the mainstream in encryption system rather than symmetric cryptosystem by above reasons. But asymmetric cryptosystem is restricted in applying to application fields by the reason it takes more times to process than symmetric cryptosystem. In this paper, the proposed cryptosystem uses an algorithm that combines block cipherment with stream ciphcrment. Proposed cryptosystem has a high stability in aspect of secret rate by means of transition of key sequence according to the information of plaintext while asymmetric /symmetric cryptosystern conducts encipherment/decipherment using a fixed key Consequently, it is very difficult to crack although unauthenticator acquires the key information. So, the proposed encryption system which has a certification function of asymmetric cryptosystcm and a processing time equivalent to symmetric cryptosystcm will be highly useful to authorize data or exchange important information.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권5호
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• pp.968-988
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• 2010

Anonymous hierarchical identity based encryption (HIBE) is an extension of identity based encryption (IBE) that can use an arbitrary string like an e-mail address for a public key, and it additionally provide the anonymity of identity in ciphertexts. Using the anonymous HIBE schemes, it is possible to construct anonymous communication systems and public key encryption with keyword search. This paper presents an anonymous HIBE scheme with constant size ciphertexts under prime order symmetric bilinear groups, and shows that it is secure under the selective security model. Previous anonymous HIBE schemes were constructed to have linear size ciphertexts, to use composite order bilinear groups, or to use asymmetric bilinear groups that is a special type of bilinear groups. Our construction is the first efficient anonymous HIBE scheme that has constant size ciphertexts and that uses prime order symmetric bilinear groups. Compared to the previous scheme of composite order bilinear groups, ours is ten times faster. To achieve our construction, we first devise a novel cancelable random blinding technique. The random blinding property of our technique provides the anonymity of our construction, and the cancellation property of our technique enables decryption.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전력기술부문
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• pp.291-293
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• 2007

SCADA (Supervisory Control and Data Acquisition) SCADA refers to the combination of telemetry and data acquisition [1]. SCADA system has been used for remote measurement and control on the critical infrastructures as well as modem industrial facilities. Electric Power system is a representative system using SCADA network for its communication. Integration between many networks and increasing threatens of terrorism have made the potential risk by cyber attacks real and bigger in power system. Recently, many researching efforts have been made on SCADA network for improving its security. In general aspect, there are already several ways to secure the system like encryption, firewall, authentication, etc. In this paper, we focus on symmetric encryption method and propose the proper key distribution method to reflect the unique characteristics of SCADA network communication.

• ETRI Journal
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• 제34권1호
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• pp.66-75
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• 2012

This paper proposes a privacy-preserving database encryption scheme that provides access pattern hiding against a service provider. The proposed scheme uses a session key to permute indices of database records each time they are accessed. The proposed scheme can achieve access pattern hiding in situations in which an adversary cannot access the inside of the database directly, by separating the entity with an index table and data table and permuting both the index and position where the data are stored. Moreover, it is very efficient since only O(1) server computation and communication cost are required in terms of the number of the data stored. It can be applied to cloud computing, where the intermediate entities such as cloud computing service provider can violate the privacy of users or patients.

• 대한전자공학회논문지SD
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• 제40권9호
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• pp.702-713
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• 2003

정보통신 및 네트워크의 급격한 발전으로 인하여 정보보호분야의 중요성은 매우 크다. 또한 사용자에 의한 서비스 수요가 증가하면서 개인정보보호에 대한 관심이 증가하였다. 이러한 이유로 대칭형 암호방식보다는 비대칭형 암호방식이 주류를 이루게 되었다. 그러나 비대칭형 암호방식은 대칭형 암호시스템에 비하여 처리속도가 낮아서 적용되는 분야가 한정된다. 그러므로 본 논문에서는 대칭형 암호시스템을 이용하여 비대칭형 암호시스템의 인증기능을 수행할 수 있도록 하는 암호시스템을 설계하였다. 제안된 암호시스템은 블록 암호방식과 스트림 암호방식을 혼용하여 사용하였다. 대칭형/비대칭형 암호시스템은 고정된 키에 의하여 암호/복호를 수행하지만 제안된 암호시스템은 평문의 정보에 의하여 키수열이 변화하도록 함으로써 비도 측면에서 매우 높은 안전성을 가지도록 하였다. 그러므로 비인가자가 키정보를 확보하여도 크랙하기가 매우 어려워진다. 그러므로 제안된 암호시스템은 대칭형 암호시스템의 처리속도와 비대칭 암호시스템의 인증기능을 가지고 있으므로 데이터 인증 또는 중요한 정보의 교환에 매우 유용하게 사용되리라 사료된다.

• 대한수학회보
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• 제46권4호
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• pp.771-787
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• 2009

We use an idea of linear representations of the symmetric group to reduce the number of communication rounds in the verification protocol, proposed in Crypto 2005 by Peng et al., of a shuffling. We assume Paillier encryption scheme with which we can apply some known zero-knowledge proofs following the same line of approaches of Peng et al. Incidence matrices of 1-subsets and 2-subsets of a finite set is intensively used for the implementation, and the idea of $\lambda$-designs is employed for the improvement of the computational complexity.

• Current Optics and Photonics
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• 제5권2호
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• pp.155-163
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• 2021

We propose a novel optical encryption scheme for cipher-feedback-block (CFB) mode, capable of encrypting two-dimensional (2D) page data with the use of two-step phase-shifting digital interferometry utilizing orthogonal polarization, in which the CFB algorithm is modified into an optical method to enhance security. The encryption is performed in the Fourier domain to record interferograms on charge-coupled devices (CCD)s with 256 quantized gray levels. A page of plaintext is encrypted into digital interferograms of ciphertexts, which are transmitted over a digital information network and then can be decrypted by digital computation according to the given CFB algorithm. The encryption key used in the decryption procedure and the plaintext are reconstructed by dual phase-shifting interferometry, providing high security in the cryptosystem. Also, each plaintext is sequentially encrypted using different encryption keys. The random-phase mask attached to the plaintext provides resistance against possible attacks. The feasibility and reliability of the proposed CFB method are verified and analyzed with numerical simulations.