• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.8C
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• pp.756-764
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• 2003

We investigate a probabilistic public key cryptosystem proposed by Paillier. It is based on the discrete logarithmic function and the messages are calculated from the modular product of two those functions, one of which has a fixed value depending on a given public key. The improvement is achieved by a good choice for the public key so that it is possible to get efficient schemes without losing the onewayness and semantic security. Also we suggest the method to get the public key for our schemes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.4
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• pp.1024-1034
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• 1998

Most public cryptosystem widely used in communication network are based on the exponentiation-arithmetic. But, cryptosystem has to use bigger and bigger key parameter to attain an adequate level of security. This situation increases both computation and time delay. Montgomery, yang and Kawamura presented a method by using the pre-computation, intermediately computing and table look-up on modular reduction. Coster, Brickel and Lee persented also a method by using the pre-computation on exponentiation. This paper propose to reduce computation of exponentiation with spare prime. This method is to enhance computation efficiency in cryptosystem used discrete logarithms.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.52 no.4
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• pp.141-147
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• 2003

Security of the electronic commercial transaction especially through the mobile communication network is gaining its significance due to rapid development of information and communication related fields. For that, some kind of cryptographic algorithm is already in use for the smart card. However, the growing needs of handling multimedia and real time communication bring the smart card into more stringent use of its resources. Therefore, we proposed a hybrid cryptosystem of the smart card to facilitate multimedia communication and real time communication.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.3
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• pp.389-395
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• 2011

Since Elliptic Curve Cryptosystems(ECCs) support the same security as RSA cryptosystem and ElGamal cryptosystem with 1/6 size key, ECCs are the most efficient to smart cards, cellular phone and small-size computers restricted by high memory capacity and power of process. In this paper, we explicitly explain methods for finite fields operations used in ECC, and then construct some composite fields over finite fields which are secure under Weil's decent attack and maximize the speed of operations. Lastly, we propose a fast multiplier over our composite fields.

• Journal of the Korea Society of Computer and Information
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• v.9 no.3
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• pp.157-161
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• 2004

In this paper, we proposed LUC cryptosystem of the methods of decryption by reduced Lehmer totient fuction in Eisenstein field. it is more efficient than original LUC crytosystem. Futhermore, use of Chinese Reminder Theorem and ambiguity problem in decrypted message can be eliminate.

• Journal of the Korea Society of Computer and Information
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• v.3 no.2
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• pp.177-182
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• 1998

This paper proposes pure master key which can be commonly used in multi-cryptographic system. It also refer to master key condition for RSA public key cryptosystem using Format's theorem and master key algorithm as well.

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.345-348
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• 2002

This paper presents new fast scalar multiplier of elliptic curve cryptosystem that is regarded as next generation public-key crypto processor. For fast operation of scalar multiplication a finite field multiplier is designed with LFSR type of bit serial structure and a finite field inversion operator uses extended binary euclidean algorithm for reducing one multiplying operation on point operation. Also the use of the window non-adjacent form (WNAF) method can reduce addition operation of each other different points.

• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.148-151
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• 2000

In recent years, security is essential factor of our safe network community. Therefore, data encryption/ decryption technology is improving more and more. Elliptic Curve Cryptosystem proposed by N. Koblitz and V. Miller independently in 1985, require fewer bits lot the same security, there is a net reduction in cost, size, and time. In this paper, we design high speed underlying field arithmetic processor for elliptic curve cryptosystem. The targeting device is VIRTEX V1000FG680 and verified by Xilinx simulator.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.337-340
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• 2001

This paper presented a new structure of RSA cryptosystem using modified Montgomery algorithm and CSA(Carry Save Adder) tree. Montgomery algorithm was modified to a radix-4 modified Booth algorithm. By appling radix-4 modified Booth algorithm and CSA tree to modular multiplication, a clock cycle for modular multiplication has been reduced to (n＋3)/2 and carry propagation has been removed from the cell structure of modular multiplier. That is, the connection efficiency of full adders is enhanced.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 1991.11a
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• pp.176-184
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• 1991

A realization of a conventional cryptosystem for personal computers using the DSP56001 digital signal processing chip is presented. An improved Lucifer-type algorithm is employed to encrypt, and executed in the DSP56001. The Diffie-Hellman method is employed to generate and distribute the key. The implemented hoard can be plugged in the I/O port of personal computers.