In common with more than two dozen other sites, popular torrent site YIFY-Torrents is blacked out in the UK by High Court order, completely unavailable by standard means. Or is it? By the time you read this article the site should be again widely available, but how was that achieved? Today TorrentFreak speaks with the site's network gurus to learn more about their technical battle with the UK's Internet censors.

In 2010 when x264 really started to take off, an opportunity was spotted by an individual called YIFY. The codec allowed the spreading of movies in a compact filesize, something which proved popular with the masses.

By August 2011 YIFY releases had become so popular they justified a platform of their own. A site bearing the same name was born and quickly grew to become a major player. By 2013 the site was receiving 700,000 visitors a day, something which placed it on Hollywood’s radar.

Perhaps inevitably, on November 22, 2013, the popular torrent site was blocked by the UK’s leading ISPs following a High Court order obtained by the major Hollywood studios. Anyone wanting to access the site could now only do so by using a web proxy, reverse proxy, VPN, or other anti-censorship tool. YIFY-Torrents wanted to do something about that.

“Our user base is the most important and integral part of Yify-Torrents, so having access restricted by major ISPs not only in the UK but also other places around the world was a big worry for us and we almost immediately started looking for solutions to the problem,” YIFY’s tech team told TorrentFreak.

“As most of us here at Yify-Torrents are based outside the focuses of large anti-piracy groups it was difficult for us to assess what was happening. Our first step was to figure out exactly how widespread the blocking was and how they were doing it.”

YIFY says their first guess was backed up a TorrentFreak report detailing findings by EZTV that ISPs were carrying out their own DNS scrapes to update their blacklists, something which later led to the accidental blocking of TorrentFreak. Time to carry out some tests.

“After a day of coding up a small test application we sent it out to some UK visitors that had reached out and expressed their interests in aiding in any way possible. Within a day we had results for two major ISPs in the country, Sky and TalkTalk. This provided the first real insight into the issue and was when we hit our first milestone!”

YIFY discovered that DNS lookups for YIFY-Torrents.com still responded with the site’s IP addresses meaning that they could rule out DNS tampering. Also, pings to YIFY’s infrastructure were replied to, meaning that the ISPs weren’t simply dropping traffic to blacklisted IP addresses. With no DNS tampering, YIFY had opportunity to bypass the blocks.

“After all the testing we came to the conclusion that Sky (and others) regularly pull IPs listed on our DNS servers and add them to their block list. This block list is then used by an advanced proxy system that redirects any requests to the blacklisted IPs to a webserver that the ISP owns and returns a stock ‘blocked page’ message,” YIFY explains.

“What this meant for us was that if we added new IPs behind yify-torrents.com they would work until Sky and friends updated their blacklist. This was our second edge on Sky. Because they did the blocking on an IP level and didn’t do anything related to domain names, we could do some fancy DNS trickery to keep the site online.”

People attempting to access YIFY-Torrents.com during the next few hours from the leading ISPs should find out the site has been unblocked. At the time of writing Virgin Media is for some reason causing problems, but a solution to that (and any others that might appear) is just a couple of clicks away.

“We have set-up a new domain name for inhibited visitors: yify-torrents.im, which should already be accessible to all. This domain was and still is running completely separately from the main site. What we were originally betting on was that in order for our new domain to be blocked, anti-piracy groups would need to get another court order to get it taken down, something that doesn’t happen overnight,” YIFY says.

But what YIFY wanted was a more permanent solution and for this they are currently using CloudFlare

“CloudFlare is an amazing CDN and security provider for small to large sites. They offer caching of services so that any static content is loaded from CloudFlare instead of the origin server,” YIFY explains.

“Along with this it offers protection because instead of the IPs of your real server being public, CloudFlare’s IPs are seen instead. This offers protection from plenty of web nasties like DDoS attacks. In fact, CloudFlare have and still do harbor some notorious sites like LulzSecurity’s site. Whilst the protection isn’t perfect (people can still submit DMCA notices and get real IP addresses), this wasn’t a problem for us as we already have a setup where the only public IPs listed are those of our front-end caches.”

At this point, YIFY returns to the EZTV story referenced earlier and why blocking CloudFlare IP addresses to get at YIFY-Torrents would be a particularly bad idea.

“Because CloudFlare provide services to something like 1,000,000 customers, any downtime would affect a large portion of the Internet. Everything from Imgur to gaming forums who use their services would go down.”

But while YIFY could use CloudFlare exclusively, they are choosing not to thanks to something called Geo DNS.

“GeoDNS allows us to hand out different IP addresses based on the location of the visitor. Our new system uses this to hand out CloudFlare IPs and only CloudFlare IPs to any UK visitor that hits our site, whilst the rest of the world gets to use our existing network.”

Details shared with TorrentFreak this morning shows that there is a real cat and mouse game going on behind the scenes, with YIFY doing everything they can to unblock their site and measures being taken by certain ISPs to hinder them. The site acknowledges that there still might be issues over the next few days while the system is fine-tuned but they hope that by sharing some of their findings other sites will able to take similar measures to thwart censorship. In any event, they believe that overall the sites will prevail.

“It’s really a giant game of cat and mouse with the supposed ‘good guys’ always playing catch up. ISPs have exhausted every single tactic in keeping sites censored and are bordering on affecting other legitimate sites like was seen with TorrentFreak and EZTV. When that sort of stuff starts happening, there really is nothing more they can do.

“Don’t get me wrong, it isn’t all smooth sailing from here on out, but we are happy to have the site up and running back in the UK for now and will keep on pushing against the ever growing censorship that is happening everywhere we look,” YIFY concludes.