Tor Browser 4.5 released! It comes with many improvements for security, privacy and usability. New Security Slider is available from the menu item Privacy and Security Settings New Disconnect search engine by default provides private Google search results without Captchas or bans. The Tor Browser also introduces a new obfs4 obfuscation protocol, which improves resistance for DPI and probing and prevents automated scanning for Tor bridges. The new Tor Browser.5 also introduces the. digital signature of the Windows packages with a hardware token donated by DigiCert CA.”]
Source: https://securityaffairs.co/wordpress/36500/digital-id/tor-browser-4-5.html