Hello nithesh2002, Encryption tab not exist in current Firefox releases. You cannot disable TLS or SSL3 in a tab (like before) but you can change that in about:config page. http://kb.mozillazine.org/security.tls.version.* If your thoughts is for [https://blog.mozilla.org/security/2014/10/14/the-poodle-attack-and-the-end-of-ssl-3-0/ POODLE Attack], note that SSLv3 will be disabled by default in Firefox 34, which will be released on Dec 1 or 2. thank you