Secure Communications

Encrypted Transmissions

SSH keys provide secure authentication between your spacecraft and mission control without requiring your GitHub account password. They use public-key cryptography, an industry-standard security model.

Why SSH Keys?

• More secure than passwords
• No typing passwords repeatedly
• Convenient for Git operations with remotes
• Resistant to brute-force attacks

Checking for Existing Keys

ls -la ~/.ssh

Look for files like id_rsa.pub or id_ed25519.pub. If they exist, you already have keys!

Generating a New SSH Key

ssh-keygen -t ed25519 -C "your.email@example.com"

Press Enter to accept the default file location. Enter a passphrase (recommended but optional).

This creates two files:

• id_ed25519: Private key (keep secret!)
• id_ed25519.pub: Public key (share with GitHub)

Starting the SSH Agent

eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519

Adding the Key to GitHub

1. Copy your public key:

cat ~/.ssh/id_ed25519.pub

2. Go to GitHub → Settings → SSH and GPG keys
3. Click "New SSH key"
4. Paste your public key
5. Give it a title (e.g., "Personal Laptop")
6. Click "Add SSH key"

Testing the Connection

ssh -T git@github.com

You should see: "Hi username! You've successfully authenticated..."

HTTPS vs. SSH

Two ways to connect to GitHub:

• HTTPS: https://github.com/user/repo.git (uses browser sign-in, a credential manager, or a token)
• SSH: git@github.com:user/repo.git (uses SSH keys)

SSH is often more convenient for frequent pushing and pulling.

Next: The Staging Bay

Your secure communications channel is established. Next, head to the staging bay and learn git add—preparing files for commit.