AES Cryptanalysis Research

Experimental cryptanalysis of the Advanced Encryption Standard (AES) through controlled laboratory experiments examining internal dynamics and mode of operation security.

Overview

This repository contains research on AES-128 cryptanalysis including:

• Avalanche effect measurement across AES rounds
• Component analysis (ShiftRows, MixColumns)
• ECB vs CBC mode security comparison
• LaTeX research paper generation

Author

• Scott Weeden - Texas Tech University
• Email: scott.weeden@ttu.edu

Project Structure

aes-cryptanalysis/
├── AES_Experiment/          # Experimental implementation
│   ├── aes_cryptanalysis.py    # Main AES implementation
│   ├── aes_modes_experiment.py # Mode comparison
│   ├── AES_Cryptanalysis_Paper.tex  # LaTeX paper
│   ├── AES_Cryptanalysis_Paper.pdf  # Compiled PDF
│   └── aes_cryptanalysis.bib       # BibTeX references
│
├── AES_Hypothesis/          # Research hypotheses
│   └── hypotheses.md           # Hypothesis document
│
└── README.md

Running Experiments

# Run AES cryptanalysis experiments
python AES_Experiment/aes_cryptanalysis.py

# Run mode comparison
python AES_Experiment/aes_modes_experiment.py

# Compile LaTeX to PDF
cd AES_Experiment
pdflatex AES_Cryptanalysis_Paper.tex

Research Hypotheses

1. H1 (Avalanche Effect): AES exhibits the avalanche property where a single bit change causes ~50% output bits to change
2. H2 (ShiftRows): ShiftRows is essential for cross-column diffusion
3. H3 (MixColumns): Standard MixColumns matrix is carefully designed for maximum diffusion
4. H4 (Key/Plaintext Flip): Key flips and plaintext flips produce equivalent diffusion
5. H5 (ECB Security): ECB mode exhibits pattern leakage
6. H6 (CBC Security): CBC mode provides semantic security

All hypotheses confirmed through experimentation.

Key Results

• Avalanche Effect: 48.4% bit change by round 3
• ShiftRows Impact: Without it, max 15.6% diffusion
• MixColumns Impact: With sparse matrix, 4.7% max diffusion
• ECB Mode: 0.5% block diversity (pattern leakage)
• CBC Mode: 100% block diversity (semantic security)

Publication

This research was conducted for CS 6343 Cryptography and Network Security at Texas Tech University.

License

MIT License

Citation

@misc{aes_cryptanalysis_weeden2026,
  author = {Scott Weeden},
  title = {AES Cryptanalysis: Avalanche Effect, Component Analysis, and Mode of Operation Security},
  year = {2026},
  school = {Texas Tech University},
  note = {CS 6343 Cryptography and Network Security}
}