To check if a website is using HTTPS encryption to protect your data:

1. Look for a lock icon in the address bar
2. Check for 'https' in the URL
3. Verify the same security settings on different pages of the website

To ensure your data is secure:

1. Keep your credentials up to date
2. Disable your browser's auto-fill features
3. Avoid using public Wi-Fi unless necessary
4. Make sure you are only submitting sensitive information to websites with HTTPS encryption