Quantum Cryptography for Autonomous Underwater Vehicles

Basics of Quantum Cryptography

1. Dr. Kamalakanta Sethi Quantum Cryptography

2. What is Quantum Cryptography Quantum cryptography is a new form of secure communication that uses the principles of quantum p hysics to protect information. Key Difference from Classical Cryptography: Classical: Security relies on solving hard math problems ( RSA -> Prime Factorization Problem , ECC -> ECDLP ). Quantum: Security relies on the laws of quantum physics → can detect eavesdropping. Main Goal: To create unbreakable encryption keys through Quantum Key Distribution (QKD). Unique Feature: If someone tries to intercept the quantum signal, it disturbs the particles (photons), and the sender & receiver immediately know the channel has been compromised.

3. Quantum Basics Photon = a tiny particle of light. Polarization = the “direction” in which the photon vibrates. Up/Down (↑ ↓) → like vertical blinds. Left/Right (→ ←) → like horizontal blinds. Diagonal (↗ ↘) → like tilted blinds. Random Choice = Both Alice and Bob use random choices for sending/reading photons. Quantum Rule = If someone tries to peek, the photons change → you know someone is spying! (Visual: blinds tilted different ways with arrows ↑, →, ↗, ↘)

4. Entalgment and Superposition

5. BB84 Quantum Key Distribution (QKD)

6. One –time Pad

7. Step 1: Alice Sends Secret Bits Alice wants to share a secret code (key) with Bob. She uses photons (light particles) to send bits (0s and 1s). She randomly chooses directions for each photon: Example: “0” = → or ↘, “1” = ↑ or ↗. The photons travel through a channel (like a fiber cable) to Bob. If Eve tries to listen in, she messes up the photons . (photon direction will change)

8. Step 2: Bob Reads the Photons Bob also guesses directions randomly when measuring photons. Sometimes he guesses right → gets the correct bit. Sometimes he guesses wrong → gets nonsense. Later, Bob tells Alice which guesses (directions) he used. Alice says “Keep these, throw away the rest.” The bits they both agree on become the shared secret key.

9. The Result (Shared Secret Key) At the end, Alice and Bob share the same secret code. If Eve was spying, she would have created errors Alice and Bob would notice. This means: Safe communication Future-proof (cannot be broken by quantum computers) Based on physics, not just hard math

10. In Summary Alice sends light particles with random directions. Bob measures them with random guesses. They compare notes and keep the matching bits. Any spy will be caught because the photons change when touched.

11. UAVs: Why Security Matters? UAVs (drones) used in: Military: Reconnaissance, border patrol, targeting. Civilian: Delivery, disaster relief, agriculture. Threats: Eavesdropping: Stealing mission data. Spoofing: Hijacking drone signals. Jamming: Disrupting communication. Traditional cryptography vulnerable → UAVs need quantum security . (write with deep sea security)

12. How Quantum Cryptography Secures UAVs System Design: UAV has a quantum transmitter/receiver. Ground Control Station (GCS) has a matching setup. They exchange quantum keys (QKD). Use keys for encrypting mission commands and video feeds. Works via: Free-Space Optical Links (laser beams). Satellite-UAV communication.