To check security:
Look for a lock icon in the upper-right corner of the Safari window. The lock icon means that the website has a certificate signifying to Safari that it’s a legitimate website and that information you exchange with it will be encrypted.
Make sure the website’s address begins with “https” (instead of “http”).
If the website is not secure, you may have been given a choice between a secure and an insecure connection when logging in to the site. Go back to the page where you logged in and check for a link to a secure login. Even if you don’t plan to view private information, it’s best to use a secure login whenever possible, to ensure that your login information is encrypted.