Lab Notes: 2025-11-15

Overview

Focused heavily on cryptography fundamentals, especially Diffie-Hellman and RSA. Multiple problem-solving sessions to understand modular arithmetic, exponentiation, and the creation of public keys. Also addressed personal focus issues and tied them into disciplined study habits.

Cybersecurity Topics Covered

• Diffie-Hellman key exchange math walkthrough.
• Computing public keys: A = g^a mod p.
• Understanding where results like 19 come from during modulo operations.
• RSA fundamentals: p, q, n, phi(n), modular inverse, e × d ≡ 1 mod φ(n).
• Learning how to correctly choose e that is coprime with φ(n).
• Understood modular notation and gcd meaning.
• BIOS access troubleshooting for HP laptops (sysadmin knowledge).

Commands / Concepts Practiced

# Modular exponentiation concept:
A = g^a mod p

# gcd (greatest common divisor)
gcd(e, phi) = 1

# RSA modular inverse
e × d ≡ 1 mod φ(n)

Notes

• Began understanding exponentiation using modulo step-by-step.
• Identified mental fatigue patterns and reinforced discipline.
• Connected cryptographic math with real-world pentesting foundation.