• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.3
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• pp.77-85
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• 2002

A Research of binary random sequence generator that uses a linear shift register had been studied since the 1970s. These generators were used in stream cipher. In general, the binary random sequence generator consists of linear shift registers that generate sequences of maximum period and a nonlinear filter function or a nonlinear combination function to generate a sequence of high linear complexity. Therefore, To generate a sequence that have long period as well as high linear complexity becomes an important factor to estimate safety of stream cipher. Usually, the maximum period of the sequence generated by a linear feedback shift register with L resistors is less than or equal to $2^L$-1. In this paper, we propose new binary random sequence generator that consist of L registers and 2 sub-characteristic polynomials. According to an initial state vector, the least period of the sequence generated by the proposed generator is equal to or ions than it of the sequence created by the general linear feedback shift register, and its linear complexity is increased too.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.4
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• pp.53-60
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• 2007

In a known plaintext scenario, fast correlation attack is very powerful attack on stream ciphers. Most of fast correlation attacks consider the cryptographic problem as the suitable decoding problem. In this paper, we introduce advanced multi-pass fast correlation attack which is based on the fast correlation attack, which uses parity check equation and Fast Walsh Transform, proposed by Chose et al. and the Multi-pass fast correlation attack proposed by Zhang et al. We guess some bits of initial states of the target LFSR with the same method as previously proposed methods, but we can get one more bits at each passes and we will recover the initial states more efficiently.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.2 s.302
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• pp.49-58
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• 2005

In this paper, we proposed a blind watermarking algerian to use characteristics of a scalar quantizer which is the recommended in the JPEG2000 and JPEG. The proposed algorithm shifts a quantization index according to the value of each watermark bit to prevent losing the watermark information during the compression by quantization. Therefore, the watermark is embedded during the process of quantization, not an additional process for watermarking, and is adaptively applied as a assigned quantizer according application areas. Before embedding process, a LFSR(Linear feedback shift register) rearranged the watermark for the security of the watermark itself and in the embedding process, a LFSR is used to hide the watermarking positions. Therefore the embedded watermark can he extracted by only the owner who knows the initial value of LFSR without the original image. The visual recognizable pattern such as a binary image was used as the watermark. The experimental results showed that the proposed algerian satisfies the robustness and imperceptibility corresponding to the major requirement of watermarking. The results showed the largest error rate to be $5.7\%$ for attack. The experimental result which compares the proposed algorithm with the Mohamed algorithm showed that the proposed algorithm was better than it, exactly $4\~5$ times for the attacks of JPEG and JPEG2000.

• Journal of IKEEE
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• v.7 no.1 s.12
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• pp.9-15
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• 2003

An optimized finite-field multiplier is proposed for encryption and error correction devices. It is based on a modified Linear Feedback Shift Register (LFSR) which has lower power consumption and smaller area than prior LFSR-based finite-field multipliers. The proposed finite field multiplier for GF(2n) multiplies two n-bit polynomials using polynomial basis to produce $z(x)=a(x)^*b(x)$ mod p(x), where p(x) is a irreducible polynomial for the Galois Field. The LFSR based on a serial multiplication structure has less complex circuits than array structures and hybrid structures. It is efficient to use the LFSR structure for systems with limited area and power consumption. The prior finite-field multipliers need 3${\cdot}$m flip-flops for multiplication of m-bit polynomials. Consequently, they need 6${\cdot}$m latches because one flip-flop consists of two latches. The proposed finite-field multiplier requires only 4${\cdot}$m latches for m-bit multiplication, which results in 1/3 smaller area than the prior finite-field multipliers. As a result, it can be used effectively in encryption and error correction devices with low-power consumption and small area.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.832-835
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• 2004

In this paper, we proposed a blind watermarking algorithm to use characteristics of a scalar quantizer which is similar with the recommended in the JPEG2000 and JPEG. This algorithm shifts a quantization index according to the value of each watermark bit to prevent losing the watermark information during the compression by quantization. Therefore, the watermark is embedded during the process of quantization, not an additional process for watermarking, and adaptively applied as an assigned quantizer according to application area. In the embedding process, a LFSR(Linear feedback shift register) is used to hide the watermarking positions. Therefore the embedded watermark can be extracted by only the owner who knows the initial value of LFSR without the original image. The experimental results showed that the proposed algorithm satisfies the robustness and imperceptibility corresponding to the major requirement of watermarking.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1503-1506
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• 1987

This paper proposes the self test method for 16 point FFT processor with systolic array architecture. To test efficiently and solve the increased hardware problems due to built-in self test, we change the normal registers into Linear Feedback Shift Registers(LFSR). LFSR can be served as a test pattern generator or a signature analyzer during self test operation, while LFSR a ordering register or a accumulator during normal operation. From the results of logic simulation for 16 point FFT processor by YSLOG, the total time is estimated in about. 21.4 [us].

• International journal of advanced smart convergence
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• v.13 no.2
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• pp.35-43
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• 2024

In this paper, we propose two 127-bit LFSR (Linear Feedback Shift Register)-based OTP (One-Time Password) generators. One is a 9-digit decimal OTP generator with thirty taps, while the other is a 12-digit OTP generator with forty taps. The 9-digit OTP generator includes only the positions of Fibonacci numbers to enhance randomness, whereas the 12-digit OTP generator includes the positions of prime numbers and odd numbers. Both proposed OTP generators are implemented on an Arduino module, and randomness evaluations indicate that the generators perform well across six criteria and are straightforward to implement with Arduino.

• Proceedings of the Korea Multimedia Society Conference
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• 2001.11a
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• pp.681-685
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• 2001

본 논문에서는 난수 발생기로써 랜덤성이 우수하고 하드웨어 설계시 고속성이 보장되어 LFSR(Linear Feedback Shift register) 대안으로 소개되고 있는 셀룰라 오토마타(CA: Cellular Automata)를 소개하고 이를 이용한 새로운 블록 암호 알고리즘을 제안한다. 제안된 블록 암호 알고리즘은 Fiestel 구조로써 라운드 함수와 키 스케쥴링 모두를 셀룰러 오토마타를 이용하여 구성함으로써 구현의 편이성과 고속성을 추구하였다. 제안 알고리즘에 대한 간단한 통계적 검정과 성능평가를 통해 기존 표준 알고리즘고의 비교를 수행하였다.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.533-536
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• 2003

본 논문에서는 전화선을 이용한 고속 홈네트워크인 HomePNA 2.0 시스템에서 HomePNA 2.0 (H2) 프레임을 만들기 위한 프레임 프로세싱 중, 다항식 나누기 연산을 통한 CRC (Cyclic Redundancy Check) 16비트 생성, HCS (Header Check Sequence) 8비트 생성 및 혼화(Scrambling) 처리에 있어서 입력 8 비트를 동시에 병렬 처리함으로써 기존의 1 비트 입력을 LFSR (Linear Feedback Shift Register)를 사용한 다항식 나누기 연산을 수행했을 때보다 빠른 속도로 H2 프레임을 구현하고자 하는 고속 처리 기법을 제시하고 이의 성능을 검증하였다.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.85-88
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• 2002

In this paper, the proposed watermark algorithm is based on energy distribution of the subband coefficients in the frequency domain and edge of the original image in the spacial domain. Out of these information, the KeyMap which decides the embedded position of watermark is produced. And then the binary watermark is embedded into the wavelet coefficient of LL3 subband using KeyMap and LFSR(Linear Feedback Shift Register).