• Title/Summary/Keyword: 의사난수열

Search Result 15, Processing Time 0.022 seconds

Analysis of nonlinear sequences based on shrinking generator (수축생성기에 기반한 비선형 수열의 분석)

  • Choi, Un-Sook;Cho, Sung-Jin;Kim, Han-Doo;An, Hyun-Joo
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.5 no.4
    • /
    • pp.412-417
    • /
    • 2010
  • In this paper, we analyze the properties of nonlinear sequence generated by the shrinking generator. Also we propose a method for recovering the original sequence from intercepted bits by analyzing phase shifts of the output sequence using the properties of sequences generated from control register.

Video Encryption using Pseudo-random numbers based on CA (CA 기반의 난수열을 이용한 동영상 암호화)

  • Yun, Jae-Sik;Li, Xiaowei;Cho, Sung-Jin;Kim, Seok-Tae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2010.10a
    • /
    • pp.759-761
    • /
    • 2010
  • In this paper, we propose a video encryption method using pseudo-random numbers based on MLCA(Maximal length Cellular Automata). Firstly, we generate a basis image which is composed with pseudo-random numbers, using MLCA. Futhermore, The original video is encrypted by computing XOR operation between the basis image and each frame of original video. The video encryption is conducted in accordance with one or two rules, and is evaluated.

  • PDF

Attack using Phase Shifts of Shrunken Sequence (수축수열의 위상이동차 공격법)

  • Choi, Un-Sook;Cho, Sung-Jin;Hwang, Yoon-Hee;Kim, Han-Doo
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.6 no.1
    • /
    • pp.97-104
    • /
    • 2011
  • Pseudo-random sequences with high linear complexity and low correlation function values are widely used in communication and cryptology. In this paper, we study the properties of interleaved sequences generated by shrinking generator. And we give a method for obtaining the shrunken sequence from a partial description of the shrunken sequence by using the phase shifting of PN sequences generated by shrinking generator.

Non-linear Extended Binary Sequence with Low Cross-Correlation (낮은 상호 상관관계를 갖는 비선형 확장 이진 수열)

  • Choi, Un-Sook;Cho, Sung-Jin;Kwon, Sook-Hee
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.16 no.4
    • /
    • pp.730-736
    • /
    • 2012
  • PN(Pseudo Noise) sequences play an important role in wireless communications, such as in a CDMA(code division multiple access) communication system. If there is a crash when multiple users simultaneously connected to a system, then PN sequences with low correlation help to minimize multiple access interference in such communication system. In this paper we propose a family of non-linear extended binary sequences with low cross-correlations and the family include $m$-sequence, GMW sequence, Kasami sequence and No sequence with optimal cross-correlation in terms of Welch bound. And we analyze cross-correlation of these sequences.

Design of Binary Sequences with Optimal Cross-correlation Values (최적의 상호상관관계를 갖는 이진 수열의 설계)

  • Choi, Un-Sook;Cho, Sung-Jin
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.6 no.4
    • /
    • pp.539-544
    • /
    • 2011
  • Balanced binary sequences of period $2^n-1(n{\geq}1)$ having the two-valued autocorrelation function have many applications in spread-spectrum communications system. In this paper we propose new nonlinear binary sequences which are constructed from Legendre sequences with the same cross-correlation as the sequences proposed by Cho. These sequences include the m-sequences, GMW sequences, Kasami sequences and No sequences which are described in terms of the trace function over a finite field. Also the proposed sequences have more low cross-correlation distribution than the quadratic form sequences proposed by Klapper.

Cryptanalysis of Shrinking Generator by Golomb's Randomness Postillate (Golomb의 공리를 이용한 Shrinking Generator의 분석)

  • 김정헌;권기호;박명진
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.4 no.2
    • /
    • pp.105-111
    • /
    • 2001
  • The shrinking generator is simple and stateable, and known that has good security properties. The bits of one output( $R_1$) are used to determine whether the corresponding bits of the second output will be used as part of the overall keystream. Two LFSRs consisting the generator generate pseudorandom sequences satisfying Golomb's postulates. We used this property to analyze the stream of LFSR $R_1$ of the generator.

  • PDF

New Decimations with 4-Valued Cross-Correlations (상호상관관계 함숫값이 4개인 새로운 데시메이션)

  • Kwon, Min-Jeong;Cho, Sung-Jin;Kwon, Sook-Hee;Kim, Jin-Gyoung;Kim, Han-Doo;Choi, Un-Sook
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.7 no.4
    • /
    • pp.827-832
    • /
    • 2012
  • In this paper, we present a new decimated Gold-like m-sequence with a binary m-sequence of period $2^n-1$. And we show that the cross-correlation function of the proposed sequence is four-valued.

Image Encryption using Shrinking Generator based on CA (CA기반의 수축생성기를 이용한 영상 암호)

  • Choi, Un-Sook;Cho, Sung-Jin;Kim, Han-Doo;Kang, Sung-Won
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.15 no.1
    • /
    • pp.179-184
    • /
    • 2020
  • Cellular automata (CA), which is known as a pseudo random number generator due to its excellent randomness, has various applications. Cho et al. designed a CA-based shrinking generator to generate a long period of nonlinear sequence. In addition, chaotic cat maps have been studied by many researchers as the complex nonlinear dynamics systems with sensitivity in initial conditions and unpredictable characteristics. In this paper, we propose a new image encryption method using nonlinear sequence generated by CA-based shrinking generator with maximum period and 3D chaotic cat map for high security.

A Study of Robust Watermarking Technique against MP3 and AAC Audio Compression (MP3 와 AAC 압축에 강인한 오디오 워터마킹 기술에 관한 연구)

  • Lee, Han-Ho;Kim, Jong-Weon;Choi, Jong-Uk
    • Proceedings of the Korea Information Processing Society Conference
    • /
    • 2001.04a
    • /
    • pp.213-216
    • /
    • 2001
  • 본 논문은 심리음향모델과 주파수변환을 이용하여 MP3 와 AAC 의 압축에서 강인하게 살아남을 수 있는 디지털 오디오 워터마킹 알고리즘에 관한 것이다. 워터마크를 의사난수열이나 이미지 등 외부 정보를 이용하지 않고 원본음악으로부터 생성시킨다는 것이 본 논문의 가장 큰 특징으로 원본 오디오로부터 생성된 워터마크는 음악과 융합되어 워터마크의 삽입여부를 일반인의 청각으로는 인식할 수 없다.

  • PDF

5-Neighbor Programmable CA based PRNG (프로그램 가능한 5-이웃 CA기반의 PRNG)

  • Choi, Un-Sook
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.17 no.2
    • /
    • pp.357-364
    • /
    • 2022
  • A pseudo-random number generator (PRNG) is a program used when a large amount of random numbers is needed. It is used to generate symmetric keys in symmetric key cryptography systems, generate public key pairs in public key cryptography or digital signatures, and generate columns used for padding with disposable pads. Cellular Automata (CA), which is useful for specific representing nonlinear dynamics in various scientific fields, is a discrete and abstract computational system that can be implemented in hardware and is applied as a PRNG that generates keys in cryptographic systems. In this paper, I propose an algorithm for synthesizing a programmable 5-neighbor CA based PRNG that can effectively generate a nonlinear sequence using 5-neighbor CA with the radius of the neighboring cell increased by 2.