• DocumentCode
    1437745
  • Title

    On the Nonlinearity of Exponential Welch Costas Functions

  • Author

    Drakakis, Konstantinos ; Requena, Verónica ; McGuire, Gary

  • Author_Institution
    Sch. of Electr., Electron. & Mech. Eng., Univ. Coll. Dublin, Dublin, Ireland
  • Volume
    56
  • Issue
    3
  • fYear
    2010
  • fDate
    3/1/2010 12:00:00 AM
  • Firstpage
    1230
  • Lastpage
    1238
  • Abstract
    We study the nonlinearity of the exponential Welch Costas functions, using the Fourier transform on Z m. These functions have been proposed for use in nonbinary cryptosystems. High nonlinearity is required to ensure resistance to linear cryptanalysis. We prove some properties of the nonlinearity of these functions, and we suggest a plausible connection of the nonlinearity to the class number of a quadratic field.
  • Keywords
    Fourier transforms; cryptography; Fourier transform; exponential Welch Costas functions; linear cryptanalysis; nonbinary cryptosystems; quadratic fields; Cryptography; Fourier transforms; Almost perfect nonlinear (APN) functions; Walsh transform; Welch Costas permutations; class number; nonlinearity;
  • fLanguage
    English
  • Journal_Title
    Information Theory, IEEE Transactions on
  • Publisher
    ieee
  • ISSN
    0018-9448
  • Type

    jour

  • DOI
    10.1109/TIT.2009.2039164
  • Filename
    5429121