Basics of Wave Physics
Overview
Teaching: 100 min
Exercises: 0 minQuestions
Key question (FIXME)
Objectives
First learning objective. (FIXME)
Basics of Wave Physics: Frequency, Wavelength, and Energy
Electromagnetic waves are fundamental to wireless communication and cybersecurity. Understanding their properties—frequency, wavelength, and energy—is crucial for designing secure systems and mitigating threats.
1. Frequency ($f$)
- Definition: The number of wave cycles that pass a given point per second.
- Unit: Hertz (Hz), where 1 Hz = 1 cycle per second.
- Formula:
f = \frac{c}{\lambda}
where:
- $f$ = frequency (Hz)
- $c$ = speed of light in a vacuum (approximately $3.0 \times 10^8 ~m/s$)
- $\lambda$ = wavelength (meters)
Relevance to Cybersecurity
- Different frequency bands are allocated for wireless communication (e.g., WiFi at 2.4 GHz and 5 GHz, Bluetooth at 2.4 GHz).
- Higher frequencies (e.g., 5G at 28 GHz, 39 GHz) allow for faster data transfer but have shorter range.
- Lower frequencies (e.g., AM/FM radio, military signals) travel further and penetrate obstacles more easily.
2. Wavelength ($\lambda$)
- Definition: The physical distance between successive wave peaks.
- Unit: Meters (m).
- Formula:
\lambda = \frac{c}{f}
- Relationship: Inversely proportional to frequency—higher frequency = shorter wavelength and vice versa.
Relevance to Cybersecurity
- Shorter wavelengths (high-frequency signals like WiFi, 5G, millimeter waves) are more easily absorbed by obstacles like walls, affecting security and coverage.
- Longer wavelengths (low-frequency signals like radio waves) can travel further and be intercepted over long distances.
3. Energy ($E$)
- Definition: The energy carried by a wave is related to its frequency.
- Unit: Joules ($J$).
- Formula:
E=hf
where:
- $E$ = energy (Joules)
- $h$ = Planck’s constant ($6.626 \times 10^{-34}~Js$ )
- $f$ = frequency (Hz)
Relevance to Cybersecurity
- Higher-energy waves (e.g., X-rays, gamma rays) can be used in radiation-based surveillance or hacking techniques.
- Microwave and infrared waves can be used in covert communication and surveillance methods.
- Low-energy waves (e.g., radio waves) are used in RFID, NFC, and WiFi, making them susceptible to eavesdropping and jamming.
Key Takeaways for Cybersecurity
| Property | Impact on Communication & Security |
|---|---|
| High Frequency (Short Wavelength) | Faster data rates, but signals are easier to block (e.g., 5G, WiFi) |
| Low Frequency (Long Wavelength) | Longer range, but more susceptible to interception (e.g., radio, RFID) |
| Higher Energy | More difficult to block but requires more power (e.g., satellite communications) |
Understanding these wave properties helps in designing secure networks, mitigating wireless attacks, and implementing defensive measures against threats like RF hacking, eavesdropping, and jamming.
Key Points
First key point. Brief Answer to questions. (FIXME)