What Are SSH Keys?
SSH keys are a pair of cryptographic keys used for secure authentication between a client and a server over the Secure Shell (SSH) protocol. They are commonly used to access remote systems securely without needing a password.
1. How SSH Keys Work
SSH keys use public-key cryptography, where two keys are generated:
🔑 Key Pair Components
Public Key (
id_rsa.pub
)- Can be shared with anyone.
- Stored on the server to allow secure access.
Private Key (
id_rsa
)- Must be kept secret and stored securely on your local machine.
- Used to authenticate and decrypt communication.
When you attempt to connect to a remote server, the server checks if your private key matches the public key stored on the server. If they match, you are granted access without entering a password.
2. Why Use SSH Keys?
✅ More Secure than Passwords – SSH keys are harder to crack than passwords.
✅ Convenient for Automation – No need to manually enter passwords every time.
✅ Prevents Brute-Force Attacks – Only the private key holder can access the system.
✅ Essential for Git Authentication – Used for services like GitHub, GitLab, Bitbucket to push/pull code securely.
3. How to Generate SSH Keys?
Step 1: Open the Terminal
On macOS/Linux, open the terminal.
On Windows, use Git Bash or PowerShell.
Step 2: Generate the SSH Key Pair
Run the following command:
🔹 -t rsa
→ Specifies RSA key type.
🔹 -b 4096
→ Sets a 4096-bit key for extra security.
🔹 -C "your_email@example.com"
→ Adds a comment (usually your email).
Step 3: Save the SSH Key
- It will ask for a filename to save the key. Press
Enter
to save it in the default location (~/.ssh/id_rsa
). - You can also set a passphrase for additional security (optional).
4. How to Use SSH Keys?
🔹 Add Your SSH Key to the SSH Agent
To ensure your key is used correctly, run:
🔹 Copy Your Public Key
To copy your public key to use on a server or Git provider:
Copy the output and add it to your remote server or GitHub/GitLab settings.
🔹 Add SSH Key to GitHub/GitLab
- GitHub: Settings → SSH and GPG keys
- GitLab: Settings → SSH Keys
5. Testing Your SSH Connection
To verify that your SSH key is working, run:
If successful, you will see a message like:
This means your SSH key is properly set up for GitHub authentication.
6. Using SSH Keys for Remote Server Access
To connect to a remote server using SSH:
If your public key is on the remote server, you can log in without entering a password.
7. Deleting or Replacing SSH Keys
To remove an old SSH key:
Then, generate a new key and update it in your Git or server settings.
🔹 Conclusion
SSH keys provide a secure, password-free way to authenticate with remote servers and Git repositories. By using SSH keys, you increase security while making authentication faster and more convenient.
🚀 Do you need help setting up SSH keys for GitHub or a remote server? Let me know! 😊