Ofcom's DCMS's own blocking easily visible to world+dog
Redact... redact... er... undo... ah... oops!
Technical klutz Ofcom* says web-blocking laws will be ineffective, and so should not be implemented. It did so today in a heavily readacted report – where the redactions were easily readable by the entire world. Ofcom has now removed the ineptly censored study and replaced it with a password-protected version.
One blacked-out passage describes "other methods available to [pirate] site operators" reads:
When moving to a new IP address a site operator may register multiple IP addresses for a given site in order to maintain service in the event that some of those individual IP addresses are blocked. This approach has legitimate purposes also. Furthermore, by setting a low "Time to Live" (TTL) Domain Name System (DNS) record value, determining the length of time that the IP address for a particular domain (expressed in seconds) remains in remote name server caches, it is easier for a site operator to move IP addresses without end users losing access. Where a low TTL is expressed the ISP DNS name server resolution cache is purged quickly thereby ensuring that newly assigned site IP addresses are retrieved from the authoritative name server and site accessibility is maintained.
Figure 13 below shows that the TTL value for "kickasstorrents" is one hour, demonstrating that any changes to IP address to DNS name are refreshed and propagated within ISP DNS servers in just over an hour.
(Figure 13 then shows the DNS record of kickasstorrents.com.)
But don't tell anyone. Ofcom* continues:
Other channels that site operators could use to widely distribute advice on how best to circumvent DNS blocking could include posting to online forums, Really Simple Syndication (RSS) or updates via micro-blogging sites such as Twitter.
Who would have guessed?
Ofcom, or rather the Department of Media, Culture and Sport, also doesn't want you to know that "advice could include changing to unblocked DNS name servers, Virtual Private Networks and proxy services or other anonymising systems. Similarly, site operators may quickly mirror or make copies of a blocked site on new top level or country code domains pointing towards new IP addresses eg www.blockedsite.cc; www.blockedsite.ru; www.blockedsite.vn; www.blockedsite.net".
It would also rather you didn't know that techniques site operators may use to undermine URL blocking include:
- Website operators providing encrypted access to their websites via Secure Sockets Layer/Transport Layer Security ie https connectivity https://www.example.com/downloads/pirate.zip;
- a site operator may run a website on a network port other than port 80;
- the site operator changing the IP address and bypassing the network routing announcements;
- a site operator registering a new domain name eg www.example.net or www.example.org;
- the blocked site offering services such as Virtual Private Networking;
- the use of anonymous web proxy or other anonymising services;
- the site operator reorganising the site structure if the blocking is conducted against specific URLs; and
- the site operator or end user encoding URLs to bypass blocking.
All of the above are mentioned un-redacted in the Ofcom report. The redacted portions are also readable in the Google cache, if you click on "view as HTML".
It's fortunate for the bungling department that nothing of commercial confidence was disclosed.
Given that Ofcom's study concludes that things that are technically difficult shouldn't be attempted, maybe it should give up writing reports altogether? Or at least not give them to the DCMS. ®
*A spokeswoman for Ofcom got in touch shortly after publication to explain that the Department of Media, Culture and Sport was responsible for the cack-handed censorship.
Hat-tip to Mark Bestford and several other Reg readers who spotted this.