Arama Sonuçları

Listeleniyor 1 - 6 / 6
  • Yayın
    Cryptanalysis of Fridrich's chaotic image encryption
    (World Scientific Publishing, 2010-05) Solak, Ercan; Çokal, Cahit; Yıldız, Olcay Taner; Bıyıkoğlu, Türker
    We cryptanalyze Fridrich's chaotic image encryption algorithm. We show that the algebraic weaknesses of the algorithm make it vulnerable against chosen-ciphertext attacks. We propose an attack that reveals the secret permutation that is used to shuffle the pixels of a round input. We demonstrate the effectiveness of our attack with examples and simulation results. We also show that our proposed attack can be generalized to other well-known chaotic image encryption algorithms.
  • 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
    Comment on "Encryption and decryption of images with chaotic map lattices" [Chaos 16, 033118 (2006)]
    (American Institute of Physics Inc., 2008-09) Solak, Ercan; Çokal, Cahit
    In this paper, we comment on the chaotic encryption algorithm proposed by A. N. Pisarchik et al. [Chaos 16, 033118 (2006)]. We demonstrate that the algorithm is not invertible. We suggest simple modifications that can remedy some of the problems we identified.
  • 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.
  • Yayın
    Algebraic break of image ciphers based on discretized chaotic map lattices
    (Elsevier Science Inc, 2011-01-01) Solak, Ercan; Çokal, Cahit
    In this paper, we provide an algebraic cryptanalysis of a recently proposed chaotic image cipher. We show that the secret parameters of the algorithm can be revealed using chosen-plaintext attacks. Our attack uses the orbit properties of the permutation maps to deduce encryption values for a single round. Once a single round encryption is revealed, the secret parameters are obtained using simple assignments.