Patents Examined by Harunur Rashic
  • Patent number: 9143317
    Abstract: Various embodiments of a computer-implemented method of information security using block cipher column rotations are described. The cipher state column rotations provide resistance to white box side channel memory correlation attacks designed to reverse-engineer a symmetric cipher key associated with the information security system. The column rotation operations can be performed on the cipher state of a block cipher, and then removed from the result, to provide obfuscation of the data when in memory, while not impacting the resulting output of the cipher or decipher operation. The method additionally includes performing a first rotation of an iteration specific cipher subkey according to the first rotation index, performing an iteration of the block cipher operations on the cipher state matrix, and rotating the columns of the cipher state matrix according to an inverse of the first rotation index.
    Type: Grant
    Filed: May 24, 2013
    Date of Patent: September 22, 2015
    Assignee: Apple Inc.
    Inventors: Benoit Chevallier-Mames, Mathieu Ciet, Thomas Icart, Bruno Kindarji, Augustin J. Farrugia