Homework 01

Introduction to Crytpography

  1. Public Key: An open cryptographic code that you can freely share with the world (like an open padlock). Anyone can use it to encrypt data for you or verify your digital signature.
  2. Private Key: A secret cryptographic code that stays strictly on your machine (like the physical key to the padlock). Only this key can decrypt data encrypted by its matching public key.
  3. What it’s used for: Secure server logins (SSH), encrypting secure emails (PGP), signing Git commits, and protecting cryptocurrency wallets.
  4. Why the private key must be protected: If someone steals your private key, they can bypass all security, decrypt your private files, and completely impersonate your digital identity.

Steps to create Keys:

  1. Run the command in the terminal: ssh-keygen -t ed25519 -C “your_email@example.com”
  2. Choose storage path: Press Enter to accept the default hidden location
  3. Set a passphrase: I setup a passphrase by typing the same key twice in the terminal
  4. Verify your created keys: the command to view the created keys: * ls -la ~/.ssh*