Arama Sonuçları

Listeleniyor 1 - 6 / 6
  • Yayın
    Comment on "Modified Baptista type chaotic cryptosystem via matrix secret key" [Phys. Lett. A 372 (2008) 5427]
    (Elsevier Science BV, 2009-09-07) Rhouma, Rhouma; Solak, Ercan; Arroyo, David; Li, Shujun; Alvarez, Gonzalo; Belghith, Safya Mdimegh
    In this comment, we analyze a recently proposed Baptista-like cryptosystem and show that it is not invertible. Others weaknesses are also reported. A modified version of this cryptosystem is proposed to show how to overcome the non-invertibility.
  • Yayın
    Cryptanalysis of a multi-chaotic systems based image cryptosystem
    (Elsevier Science BV, 2010-01-15) Solak, Ercan; Rhouma, Rhouma; Belghith, Safya Mdimegh
    This paper is a cryptanalysis of a recently proposed multi-chaotic systems based image cryptosystem. The cryptosystem is composed of two shuffling stages parameterized by chaotically generated sequences. We propose and implement two different attacks which completely break this encryption scheme.
  • Yayın
    Cryptanalysis of a cryptosystem based on discretized two-dimensional chaotic maps
    (Elsevier Science BV, 2008-11-17) Solak, Ercan; Çokal, Cahit
    Recently, an encryption algorithm based on two-dimensional discretized chaotic maps was proposed [Xiang et al., Phys. Lett. A 364 (2007) 252]. In this Letter, we analyze the security weaknesses of the proposal. Using the algebraic dependencies among system parameters. we show that its effective key space can be shrunk. We demonstrate a chosen-ciphertext attack that reveals a portion of the key.
  • Yayın
    Constructing a WordNet for Turkish using manual and automatic annotation
    (Assoc Computing Machinery, 2018-05) Ehsani, Razieh; Solak, Ercan; Yıldız, Olcay Taner
    In this article, we summarize the methodology and the results of our 2-year-long efforts to construct a comprehensive WordNet for Turkish. In our approach, we mine a dictionary for synonym candidate pairs and manually mark the senses in which the candidates are synonymous. We marked every pair twice by different human annotators. We derive the synsets by finding the connected components of the graph whose edges are synonym senses. We also mined Turkish Wikipedia for hypernym relations among the senses. We analyzed the resulting WordNet to highlight the difficulties brought about by the dictionary construction methods of lexicographers. After splitting the unusually large synsets, we used random walk-based clustering that resulted in a Zipfian distribution of synset sizes. We compared our results to BalkaNet and automatic thesaurus construction methods using variation of information metric. Our Turkish WordNet is available online.
  • Yayın
    Cryptanalysis of a chaos-based image encryption algorithm
    (Elsevier Science BV, 2009-03-30) Çokal, Cahit; Solak, Ercan
    A chaos-based image encryption algorithm was proposed in [Z.-H. Guan, F. Huang, W. Guan, Phys. Lett. A 346 (2005) 153]. In this Letter, we analyze the security weaknesses of the proposal. By applying chosen-plaintext and known-plaintext attacks, we show that all the secret parameters can be revealed.
  • Yayın
    Algebraic break of a cryptosystem based on discretized two-dimensional chaotic maps
    (Elsevier Science BV, 2009-03-30) Solak, Ercan; Çokal, Cahit
    Recently, a cryptosystem based on two-dimensional discretized chaotic maps was proposed [T. Xiang, et al., Phys. Lett. A 364 (2007) 252]. In this Letter, we cryptanalyze the proposal using algebraic methods. We give three different attacks that yield all the secret parameters of the cryptosystem.