Secure Communications

Encrypted Transmissions

SSH keys provide secure, password-free authentication between your spacecraft and mission control. They use public-key cryptography—industry standard security.

Why SSH Keys?

• More secure than passwords
• No typing passwords repeatedly
• Required for many Git operations
• Can't be brute-forced

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 New SSH Key

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

Press Enter to accept 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 SSH Agent

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

Adding 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 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 (requires password/token)
• SSH: git@github.com:user/repo.git (uses SSH keys)

SSH is more convenient for frequent pushing/pulling.

Next: Transmitting to Space

Your secure communications channel is established. Now let's push your code to GitHub!