Quantum Key Distribution Simulator

This project is a simple simulation of a quantum key distribution (QKD) system using Qiskit, a quantum computing framework. The simulation demonstrates the generation of a shared secret key between two parties, Alice and Bob, using quantum principles. It leverages the no-cloning theorem and the uncertainty principle to ensure the security of the key distribution process.

Features

• Simulation of quantum key distribution using random bases.
• Generation of a shared secret key between two parties.
• Use of Qiskit for quantum circuit simulation.

Prerequisites

Before running this simulation, you will need to have Python installed on your system. Additionally, the Qiskit library and NumPy must be installed. These can be installed using pip:

pip install qiskit numpy

Usage

The script performs the following steps to simulate quantum key distribution:

1. Initialization: Sets up the number of qubits/bits for the key and randomly selects bases for Alice and Bob.
2. Qubit Preparation: Alice prepares qubits in random states ('0' or '1') according to her bases.
3. Measurement: Bob measures the qubits according to his bases.
4. Key Extraction: A shared key is extracted where Alice's and Bob's bases match.

To run the simulation, simply execute the script:

python alice_and_bob.py

Output will display the shared key where Alice's and Bob's measurement bases matched.

Code Structure

• prepare_qubits(circuit, qubit_idx, state, basis): Function to prepare qubits in a specified state and basis.
• measure_qubits(circuit, qubit_idx, basis): Function to measure qubits in a specified basis.
• The main script initializes the quantum circuit, prepares and measures qubits, executes the circuit, and extracts the shared key.