Explore fast correlation attacks over extension fields and large-unit linear approximations in cryptanalysis in this conference talk. Delve into traditional stream ciphers, the concept of fast correlation attacks, and large-unit linear approximations. Examine the SEI of a distribution and generalized pseudo-linear functions modulo 2. Learn about the complexity analysis and models for fast correlation attacks over extension fields. Investigate the SNOW 2.0 ISO/IEC 18033-4 standard stream cipher, including its byte-wise linear approximation and fast correlation attacks. Conclude with improved results, open problems, and future work in this area of cryptography.
Fast Correlation Attacks over Extension Fields, Large Unit Linear Approximation and Cryptanalysis
Overview
Syllabus
Intro
Outline
Traditional Stream Ciphers before eSTREAM
Fast Correlation Attacks (1)
Large-unit Linear Approximations
SEI of a Distribution
An Example of Large-unit Approximation
GPLFM: Generalized Pseudo-Linear Function Modulo 2
Definitions
An Example of GPLFM
Computing the Distribution of GPLFM (1)
The Complexity Analysis
An Example of Algorithm 1 (1)
Model for Fast Correlation Attacks over Extension Fields (1)
The Basic Idea
Generation of Parity Checks and Decoding the Codec
Decoding with Statistical Theory
Decoding Algorithm
SNOW 2.0: ISO/IEC 18033-4 Standard Stream Cipher
The Byte-wise Linear Approximation of SNOW 2.0
Computing the Distribution of S-box and Modular Addition
The Bytewise Linear Approximation of SNOW 2.0
Fast Correlation Attack on SNOW 2.0
Improved Results
Conclusions
Open problems and Future Work
Taught by
TheIACR
