apostolescus / naevia

Naevia is a platform demonstrating the usage of the Hill Climbing optimization technique (only for local optima solutions) and N-grams frequency for cryptanalysis.

Naevia

Description

Naevia is a platform demonstrating the usage of the Hill Climbing optimization technique (only for local optima solutions) and N-grams frequency for cryptanalysis. Its functionalities, which are available through a web interface, are:

• encryption with classic ciphers:
  • Caesar;
  • Vigenere;
  • substitution;
• decryption via:
  • brute-force;
  • Hill Climbing.

Observations

To improve the convergence to the solution (the real plaintext), the following preliminary steps can be done:

• running the decryption multiple time (it starts at each run from a different random value, maybe God will have mercy on you once);
• increase ciphertext size (if possible); and
• shorten key length (if possible).

Limitations of the current version of the platform are some fixed parameters:

• the N-grams length (4);
• the number of keys generated into the brute-force process (3500); and
• the length of the Vigenere key that is brute-forced (12).

Demos

1. Encryption with the substitution cipher. Decryption via brute-foce
2. Encryption with the Caesar cipher. Decryption via Hill Climbing
3. Encryption with the Vigenere cipher. Decryption via Hill Climbing
4. Encryption with the substitution cipher. Decryption via Hill Climbing

Setup

1. install Python3 and Node.js
2. set up and run the server

cd backend
pip3 install -r requirements.txt
python3 server.py

3. set up and run the user interface

cd user-interface
npm install
npm start

Resources

User Interface

• React
• React Bootstrap
• axios
• Victory
• React Icons
• logo from Icons8
• background animation from CodePen

Backend

• Python3
• Flask
• Flask-CORS

Further Improvements

• solving the above mentioned limitations
• more parameter tuning