Solvatore

Security Algorithms

Solvatore Cryptanalysis Tool

Solvatore is a specialized tool designed to assist in the cryptanalysis of cryptographic primitives. It simplifies the process of finding integral distinguishers using the bit-based division property.

Overview

The primary objective of Solvatore is to identify distinguishers that allow a researcher to differentiate a cryptographic primitive from a truly random function. These distinguishers are often the first step in constructing powerful key-recovery attacks.

Integral Distinguishers

The tool searches for sets of inputs where certain output bits are “balanced.” A bit is considered balanced if the XOR sum of that bit across all outputs is zero with a probability of 1.

Key Features

Division Property

Implements bit-based division property analysis for modern block ciphers.

Design Flexibility

Supports various design strategies: S-boxes, bit permutations, modular addition, and matrix multiplications.

Python Integration

Built with Python, leveraging pycryptosat for SAT-based solving of division trails.

Easy Modeling

Simple API for describing cipher structures and round functions.

Getting Started

Installation

Install Dependencies Solvatore requires the pycryptosat package.
Terminal window
```
pip install pycryptosat
```
Python Environment Compatible with both Python 2 and Python 3.

Example: Analyzing PRESENT

To analyze a cipher like PRESENT, you define its structure and use the Solvatore solver to check for balanced bits.

from solvatore import Solvatore
from ciphers import present

cipher = present.present
rounds = 9

solver = Solvatore()
solver.load_cipher(cipher)
solver.set_rounds(rounds)

# Check if bit 0 is balanced after 9 rounds with specific active bits
active_bits = {i for i in range(1, 64)} # Bit 0 is constant
if solver.is_bit_balanced(0, rounds, active_bits):
    print("Found distinguisher!")

Technical Components

Core Classes

CipherDescription: Used to model the internal state and operations of the primitive.
Solvatore: The main engine that processes the cipher description and evaluates division properties.

Supported Operations

S-box Application: Map input bits to output bits through non-linear tables.
Permutations: Arbitrary bit-level shuffling.
Linear Layers: Support for complex linear transformations.