SSL connections encrypt the information traveling between your computer and the website. They are usually recognized by a web address that starts with a "https" or a browser lock icon. This technology is used by many websites including online banking sites and e-commerce websites.
What does secure search mean?
Searching on https://www.google.com creates a secure connection between you and Google. This helps protect your search terms and your search results page from being intercepted by a third party on your network.
The service includes a modified logo that helps you identify that you are searching using SSL. But as always, never forget to check the address bar for a "https" and the browser lock.
Google SSL Beta
The secure search service has been currently launched in the beta mode. This is because it covers only the core Google web project. Hence, while searching using SSL, you won't find links to offerings like Image search and Maps, for the most part does not support SSL at this time. However, Google will continue to add SSL encryption features to other search offerings too.
Since, SSL connections requires additional time to set up the encryption between your browser and the remote web server, your search over SSL will be slightly slower than regular Google search.