1. Quantum Encryption

2. Conventional Private Key Encryption: Substitution: First known use was by Caesar to communicate to generals during war Improved by Vigenere’s Cipher Very weak to frequency cryptanalysis

3. Transposition: Rearranges the letters systematically but does not change their value Still weak to frequency and and common word attacks

4. One-time pad: Similar to substitution Adds a randomly-generated key to the message Absolutely secure because the key is longer than the message and used only once

5. Overview of Conventional Encryption: Secure for private use, but requires secure transmission of private key A variation on private key encryption, public key encryption, provides a workaround for key transmission on the internet, but if intercepted is not 100% secure

6. Quantum Cryptography Points of Interest Provides 100% secure transmission of a private key of unlimited length Requires uninterrupted photon stream for transmission The original message is encoded and sent via quantum polarities of the light

7. Fiber Optic Cable For communications, many hair-thin pieces are used because they transmit better than one thick piece For normal data transmission pulses of light are used, and travel much better than the quantum polarities used for quantum transmission

8. Usual Process of Fiber Optic Communication Pulses of light are sent through fiber optics to relay huts Quantum Cryptography Message is encrypted and sent in quantum polarities of the light

9. Polarization Describes the vibrational direction of the electric field associated with the light

10. Continuous Photon Stream Requires unbroken length of fiberoptic cable Sensitive to any interception, due to uncertainty principle

11. The FTIR: Fourier Transform Infrared spectrometer Transmits the full IR spectrum Analyzes the full spectrum simultaneously Automatically graphs data Beam splitter Range of motion of mirrors Light source and detector Advantages:Limiting Factors:

12. FTIR and Fiber Optics: What we did Acquired FTIR drivers license Acquired fiber optic cable Set up consisted of a ring stand suspending the fiber optic cable in line with FTIR source and detector Ran a series of scans on one sample of fiber optic cable

13. Results Wave number % Transmittance