Ji-Woong Jang

LG Electronics, Sŏul, Seoul, South Korea

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Publications (39)11.56 Total impact

  • Young-Sik Kim · Sujan Raj Shrestha · Ji-Woong Jang
    [Show abstract] [Hide abstract] ABSTRACT: Large prime numbers are one of inevitable ingredients in the public key crypto-systems. However, the decision of the primality requires significant computational resources. In this paper, we proposed two efficient methods to generate large prime numbers. Firstly, an accelerating method by utilizing pre-installed modular multiplier which is used to calculate public key algorithm is proposed. Secondly, new improved algorithm which reduces computational resources is presented. In the latter algorithm, the requirement for the related parameters are reinforced in order to prevent generating random numbers with small prime factors. In addition, by slightly releasing the requirement for the parameters, it is possible to remove the unit generation procedure in Joye and Paillier's scheme. Through these modifications, it is possible to obtain new efficient prime number generation algorithm.
    No preview · Conference Paper · Dec 2011
  • Ji-Woong Jang · Young-Sik Kim · Sang-Hyo Kim
    [Show abstract] [Hide abstract] ABSTRACT: In this paper, we study the autocorrelation property of quaternary sequences. Firstly, we will determine the minimum bound for the maximum magnitude of non-trivial autocorrelation values according to its weight function and period. Secondly, we derive necessary and sufficient conditions for balance property with respect to the correlation values and the weight function of quaternary sequences.
    No preview · Article · Oct 2011
  • Ji-Woong Jang · Sang-Hyo Kim · Young-Sik Kim
    [Show abstract] [Hide abstract] ABSTRACT: A Construction of Quaternary Low Correlation Zone Sequence Sets from Binary Low Correlation Zone Sequence Sets Improving Optimality
    No preview · Article · Aug 2011 · IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences
  • Source
    Young-Sik Kim · Ji-Woong Jang · Dae-Woon Lim
    [Show abstract] [Hide abstract] ABSTRACT: A true random number generator (TRNG) is widely used to generate secure random numbers for encryption, digital signatures, authentication, and so on in crypto-systems. Since TRNG is vulnerable to environmental changes, a deterministic function is normally used to reduce bias and improve the statistical properties of the TRNG output. In this paper, we propose a linear corrector for secure TRNG. The performance of a linear corrector is bounded by the minimum distance of the corresponding linear error correcting code. However, we show that it is possible to construct a linear corrector overcoming the minimum distance limitation. The proposed linear corrector shows better performance in terms of removing bias in that it can enlarge the acceptable bias range of the raw TRNG output. Moreover, it is possible to efficiently implement this linear corrector using only XOR gates, which must have a suitable hardware size for embedded security systems.
    Preview · Article · Feb 2010 · Etri Journal
  • Ji-Woong Jang · Young-Sik Kim · Sang-Hyo Kim
    [Show abstract] [Hide abstract] ABSTRACT: We propose an extension method of quaternary low correlation zone (LCZ) sequence set with odd period. From a quaternary LCZ sequence set with parameters (N, M, L, 1), the proposed method constructs a new quaternary LCZ sequence set with parameters (2N, 2M, L, 2), where N is odd. If the employed LCZ sequence set in the construction is optimal, the extended LCZ sequence set becomes also optimal where N = kL, L > 4, and k > 2. Copyright © 2010 The Institute of Electronics, Information and Communication Engineers.
    No preview · Article · Feb 2010 · IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences
  • Ji-Woong Jang · Young-Sik Kim · Sang-Hyo Kim · Dae-Woon Lim
    [Show abstract] [Hide abstract] ABSTRACT: In this paper, two new construction methods of quaternary periodic complementary sequence (PCS) sets are proposed using a binary PCS set with even period. The proposed methods apply the Gray mapping to a binary PCS set. The only necessary condition to apply the proposed methods is that the employed binary PCS set should have an even period.
    No preview · Article · Feb 2010 · Advances in Mathematics of Communications
  • Ji-Woong Jang · Sang-Hyo Kim · Young-Sik Kim · Dae-Woon Lim
    [Show abstract] [Hide abstract] ABSTRACT: This paper provides two construction methods of sequence using the Gray mapping. In the first method, a quaternary sequence with Rmax = 2 for N ≡ 2 (mod 4) which is the same as the best known Rmax, is proposed. The sequence is constructed by the Gray mapping of a binary sequence with even period and its half-period shift. The resulting quaternary sequence has the same autocorrelation distribution with that of the employed binary sequence. From binary sequences with optimal autocorrelation for even period such as Sidel'nikov sequences, Ding-Helleseth-Martinsen (DHM) sequences, and sequences from the images of polynomials, etc., we can construct quaternary sequences with Rmax = 2 for period N ≡ 2 (mod 4) and Rmax = 4 for period N ≡ 4 (mod 4). In constrast to the previous quaternary sequences separately designed, new quaternary sequences are constructed from many existing binary sequences with optimal autocorrelation. In the second construction, optimal quaternary LCZ sequence sets are derived from binary LCZ sequence sets which are not necessarily optimal. To the best of our knowledge, it is the first result to obtain an optimal LCZ sequence set from a non-optimal LCZ sequence set, while there are constructions to obtain LCZ sequence sets from another LCZ sequence set. Moreover, since the parameters of new quaternary LCZ sequence set in the second method are determined by the parameters of the binary LCZ sequence set, it is possible to obtain flexible quaternary LCZ sequence sets by using flexible binary LCZ sequence sets.
    No preview · Article · Jan 2010
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    Young-Sik Kim · Ji-Woong Jang · Sang-Hyo Kim · Jong-Seon No
    [Show abstract] [Hide abstract] ABSTRACT: We propose a new construction of quaternary sequences using the reverse Gray mapping of a pair of binary Sidel'nikov sequences. The proposed construction provides sequences of even period N with the maximum nontrivial auto-correlation magnitude, R<sub>max</sub> = 2. For N ¿ 0 mod 4, the new quaternary sequences have the optimal R<sub>max</sub> = 2 and are almost-balanced in contrast to the only earlier optimal construction S<sub>j</sub>.
    Preview · Conference Paper · Aug 2009
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    Young-Sik Kim · Ji-Woong Jang · Sang-Hyo Kim · Jong-Seon No
    [Show abstract] [Hide abstract] ABSTRACT: In this paper, for an odd prime p, new quaternary sequences of even period 2p with ideal autocorrelation property are constructed using the Legendre sequences of period p. The distribution of autocorrelation function of the proposed quaternary sequences is also derived.
    Preview · Conference Paper · Aug 2009
  • Source
    Ji-Woong Jang · Jong-Seon No · Young-Sik Kim · Sang-Hyo Kim
    [Show abstract] [Hide abstract] ABSTRACT: In this paper, for an odd prime p, new quaternary sequences of even period 2p with ideal autocorrelation property are constructed using the binary Legendre sequences of period p. For the new quaternary sequences, two properties which are considered as the major characteristics of pseudo-random sequences are derived. Firstly, the autocorrelation distribution of the proposed quaternary sequences is derived and it is shown that the autocorrelation values of the proposed quaternary sequences are optimal. For both p ≡ 1 mod 4 and p ≡ 3 mod 4, we can construct optimal quaternary sequences while only for p ≡ 3 mod 4, the binary Legendre sequences can satisfy ideal autocorrelation property. Secondly, the linear complexity of the proposed quaternary sequences is also derived by counting non-zero coefficients of the discrete Fourier transform over the finite field Fq which is the splitting field of x2p - 1. It is shown that the linear complexity of the quaternary sequences is larger than or equal to p or (3p + 1)/2 for p ≡ 1 mod 4 or p ≡ 3 mod 4, respectively. Copyright © 2013 The Institute of Electronics, Information and Communication Engineers.
    Preview · Conference Paper · Aug 2009
  • Ji-Woong Jang · Sang-Hyo Kim
    [Show abstract] [Hide abstract] ABSTRACT: A quaternary sequence is constructed by Gray mapping of a binary sequence with even period and its shift. The autocorrelation of the new quaternary sequence is the same as that of the binary sequence employed. Quaternary sequences with the maximum autocorrelation 2 can be obtained by the construction for period N ≡ 2 (mod 4).
    No preview · Article · Aug 2009 · IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences
  • Sang-Hyo Kim · Young-Sik Kim · Ji-Woong Jang
    [Show abstract] [Hide abstract] ABSTRACT: In this paper, we suggest two construction methods of quaternary low and zero correlation zone (LCZ and ZCZ) sequence set. The new con- struction methods use a binary LCZ/ZCZ sequence set and the Gray mapping to produce new quaternary LCZ/ZCZ sequence sets. The parameters of the generated quaternary LCZ/ZCZ sequence set are the same as those of the em- ployed binary LCZ/ZCZ sequence set. That means, an optimal quaternary LCZ/ZCZ sequence set can be constructed from an optimal binary LCZ/ZCZ sequence set.
    No preview · Article · May 2009 · Advances in Mathematics of Communications
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    Ji-Woong Jang · Young-Sik Kim · Dae-Woon Lim
    [Show abstract] [Hide abstract] ABSTRACT: In this paper, for even integer N, we propose a new construction method of quaternary low correlation zone(LCZ) sequence set from a binary LCZ sequence set with parameters (N,M,L,). Proposed method applies the inverse gray mapping from Krone and Sarwate to binary LCZ sequences and their phase shifts. The only needed condition of binary LCZ sequence set used in this construction is even period.
    Preview · Article · Jan 2009
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    Ji-Woong Jang · Young-Sik Kim · Dae-Woon Lim
    [Show abstract] [Hide abstract] ABSTRACT: In this paper, we propose a new construction method of binary low correlation zone (LCZ) sequence set. New construction method applies Gray mapping to conventional quaternary LCZ sequence set that has specific property. The period of new binary sequence set is twice as that of used sequence set in construction, and maximum magnitude of correlation value within the LCZ and cardinality of new set is also twice as those of used quaternary sequence set. But the LCZ size is the same with that of used sequence set. If the used Quaternary sequence set is optimal, the constructed binary sequence set is optimal with high probability.
    Preview · Article · Jan 2009
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    Ji-Woong Jang · Sang-Hyo Kim · Dae-Woon Lim
    [Show abstract] [Hide abstract] ABSTRACT: In this paper, using the binary (N,M,L,1) low correlation zone(LCZ) sequence set with specific property, we propose the construction method of a quaternary LCZ sequence set with parameters (2N,2M,L,2). The binary LCZ sequence using this method must have period mod 4, balance property, and specific correlation property. The proposed method is modified from the construction method of binary LCZ sequence set by using binary LCZ sequence with specific condition proposed by Kim, Jang, No, and Chung[4].
    Preview · Article · Jan 2009
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    Ji-Woong Jang · Sang-Hyo Kim · Dae-Woon Lim
    [Show abstract] [Hide abstract] ABSTRACT: In this paper, we propose a quaternary sequence with good autocorrelation property. New quaternary sequence is generated by using inverse Gray mapping and binary sequence with ideal autocorrelation. And the maximum magnitude of nontrivial correlation value is 3. Proposed quaternary sequence has only one 1 in one period, so called almost binary sequence. Therefore the balance property is not good, but value of its weight function is nearly 0.
    Preview · Article · Jan 2009
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    Young-Sik Kim · Ji-Woong Jang · Dae-Woon Lim
    [Show abstract] [Hide abstract] ABSTRACT: The path key establishment phase in the wireless sensor network is vulnerable to Byzantine attack. Huang and Hedhi proposed a Byzantine resilient multi-key establishment scheme using a systematic RS code, which has shortcomings of exposing a part of message symbols and inefficient transmission. In this paper, we propose a new Byzantine resilient multi-path key establishment scheme in which direct message symbols are not exposed to an adversary and are more efficiently transmitted the RS-encoded symbols to the destination node. In the Proposed scheme, a non-systematic RS code is used to transmit a generated indirect secret key and each encoded symbol is relayed through available paths between two sensor nodes. If enough symbols are collected at the destination node, it is possible to reconstruct the secret message through RS decoding.
    Preview · Article · Jan 2009
  • Ji-Woong Jang · Sang-Hyo Kim
    [Show abstract] [Hide abstract] ABSTRACT: In this paper, using the binary (N,M,L,1) low correlation zone(LCZ) sequence set with specific properties, we propose a construction method of quaternary LCZ sequence sets with parameters (2N,2M,L,2). Binary LCZ sequences for the construction must have period N equiv 3 mod 4, the balance property, and proper correlation property. The new method is modified from the construction of binary LCZ sequence set by using binary LCZ sequence with the condition proposed by Kim, Jang, No, and Chung.
    No preview · Article · Dec 2008
  • Source
    Ji-Woong Jang · Jung-Soo Chung · Jong-Seon No
    [Show abstract] [Hide abstract] ABSTRACT: In this paper, we proposed a new quaternary low correlation zone(LCZ) sequence set with parameters (2(2<sup>n</sup> - 1),M, L, 2). The new LCZ sequence set is constructed from the binary sequence with ideal autocorrelation of period 2<sup>n</sup> - 1. The proposed construction method corresponds to the generalization of the construction method of binary LCZ sequence set by using binary sequence with ideal autocorrelation proposed by Kim, Jang, No, and Chung [1].
    Preview · Conference Paper · Aug 2008
  • [Show abstract] [Hide abstract] ABSTRACT: In this paper, a new extending method of q-ary low correlation zone(LCZ) sequence sets is proposed, which is a generalization of binary LCZ sequence set by Kim, Jang, No, and Chung. Using this method, q-ary LCZ sequence set with parameters (N,M,L, isin) is extended as a q-ary LCZ sequence set with parameters (pN, pM, plfloor(L + 1)/plfloor - 1, pisin), where p is prime and p|q.
    No preview · Conference Paper · Aug 2008

Publication Stats

269 Citations
11.56 Total Impact Points

Institutions

  • 2010-2011
    • LG Electronics
      Sŏul, Seoul, South Korea
    • University of California, San Diego
      • Department of Electrical and Computer Engineering
      San Diego, California, United States
  • 2009
    • Ulsan College
      Ulsan, Ulsan, South Korea
  • 2005-2006
    • Seoul National University
      • School of Electrical Engineering and Computer Sciences
      Sŏul, Seoul, South Korea
    • Hong-ik university
      United States
  • 2004
    • University of Seoul
      Sŏul, Seoul, South Korea