Just over a week ago, the High Court in the UK ruled that ISPs in the country must block access to notorious file sharing site The Pirate Bay. Since that ruling, only Virgin Media has complied with the demand, and that resulted in their website getting taken offline after Anonymous targeted it with a DDoS attack. There are more serious problems for ISPs than hacktivist retaliation over the enforcement of this ruling though; blocking access to something on the Internet is very hard indeed.
When you type in the web address for The Pirate Bay (https://thepiratebay.se), the first thing your browser does is send a query to a DNS server to translate the domain name (thepiratebay.se) into an IP address (22.214.171.124). Without this vital step, your browser is unable to make any connections to The Pirate Bay at all, so one way to block access would be to have the DNS server respond with a fake or invalid IP address. All ISPs have their own DNS servers, and these are usually set as the default in home routers, so this is easy to do. However, this default can be overridden, sometimes on the router itself, but also on your home computer. To get around this type of block, you would simply have to tell your computer to get The Pirate Bay’s IP somewhere else.
The other popular method for blocking content is to block connections to the IP addresses themselves. The ISP will collect all IP addresses that correspond to the site that needs to be blocked, and when connections to that IP are detected, they are either dropped, or routed somewhere else. In the case of Virgin Media’s block of The Pirate Bay, it seems that this is the method they are using, with all traffic destined for The Pirate Bay’s IPs being routed to Virgin Media’s servers instead.
The main problem with this type of filtering is that it also blocks any other websites that are hosted at the same IP address. This isn’t an issue with The Pirate Bay, who own and operate their own IP addresses and have dedicated servers, but could be if this type of blocking is widely used in the future. For instance, this blog is hosted on a dedicated server along with several other websites, one of which is my personal site (adrianhayter.com). If some ISP were to decide that cryptogasm.com needed to be blocked, and they blocked its IP address, then access to adrianhayter.com would also be blocked. That’s not good at all.
Although IP filtering is harder to get around than DNS filtering, it is still possible by using proxies.
Proxy servers (proxies) are servers dotted around the Internet which allow you to forward requests and receive responses through them. As long as the proxy’s ISP isn’t blocking the content you seek, you will be able to access it. There are many proxy servers out there on the Internet, including ones that have been set up to directly counter the blocks on The Pirate Bay.
There are some problems with using proxies though; the main one being that they tend to be much slower than accessing the site normally. However, this is a small price to pay to avoid censorship. The good thing about proxies is that they can be based anywhere, and so blocking access to them becomes almost impossible, as new ones will emerge all the time. The one thing that ISPs can do to counter the use of proxies is to use deep packet scanning.
Deep Packet Scanning
When handling the packets of data that you have either sent or have requested, your ISP typically scans the headers in order to send them on to the correct locations. However, they do have the ability to scan the bodies of the packets as well, and with the right analysis could be able to detect whether the content inside came from The Pirate Bay. Luckily, this technique is easily mitigated by using HTTPS, which means that all data transmitted between yourself and The Pirate Bay (or the proxy) encrypted.
So, if you are using a proxy to gain access to The Pirate Bay, or another blocked website, make sure that the proxy itself supports HTTPS (usually denoted by a padlock or green tick in your address bar). The two proxies I listed above both support it, so they should be fine to use.
Don’t get me wrong, I don’t condone piracy, but I also don’t think the solution to it lies with blocking good websites (The Pirate Bay has a lot of legal content, as do other torrenting sites). In my opinion, the main reason people pirate things is because it is easy to do so. People do not mind paying for things, but they want to pay for things on their terms, which is why services like Spotify and Netflix are so popular.
The solution to piracy is for the copyright owners to embrace change, and to start services of their own, which allow their customers to buy a single song rather than the entire album, or a few episodes of their favourite TV show and not the box set. This popular cartoon by The Oatmeal lays the argument out quite neatly.
Update (25/5/2012): The Pirate Bay recently announced a new IP address which they can be reached at: 126.96.36.199.