How does proxy bypass firewall filter?

How ip proxy bypass firewall filter, like GFW in China?

• Answer:

  All content-filter-firewall work by doing deep-packet-inspection of the traffic passing through it. Once it matches the blacklisted 'keywords' [or] it identifies the blacklisted 'destination-website', it blocks those traffic from passing through. Bypassing the 'blacklist-keyword-firewall' is easy as long as your intended website supports encryption ( the URL for these websites start will start with https:// instead of http:// ). Thats the reason all banking websites are encrypted so that no one can capture your credentials by deep-packet-inspection. The above method is applicable only if your intended website is reachable in first place. But if your desired website itself is blocked by your ISP, you can try to use an encrypted Proxy server preferably located out-side your country. Encrypted proxies hide the actual indented website you are trying to reach by encapsulating/tunneling the actual traffic from your browser in a encypted payload. (simply put ... by scrambling your browsing traffic ) This makes it impossible for the ISP to do a deep-packet-inspaction on such traffic. Getting access to encrypted proxy might be tricky, because ISP's regularly search for such proxies and block access to them. So you need to keep hunting for new encrypted proxies regularly. One of the most practical ways of using encrypted Proxies and also to automate the search for available proxies is to use the TOR projects open network and proxy. Its pretty simple you can visit their website and download the TOR Browser URL: https://www.torproject.org/ if you want to use TOR from the iOS and Android device following are the options available iOS : 'Onion Browser' : http://itunes.apple.com/us/app/onion-browser/id519296448?mt=8 Android : 'Orbot: Tor on Android' : https://play.google.com/store/apps/details?id=org.torproject.android&hl=en