Under the radar

[David]

The techniques of DRM are varied but in principle it's like this:

1) Content is encrypted in a manner which ties the encryption to a 
specific and UNIQUE device (your specific PC / Phone / Device).
2) Content is streamed to that device and decrypted using keys only 
applicable for that device (it won't decrypt on another computer).
3) For downloaded and stored content on your local drive, the encryption 
and permissions impose a strict duration.... you can backup the file (in 
encrypted form) - it's impossible to stop you. But you can't decrypt it 
after the valid duration has expired. Thus '1 month' limits are enforced.

Quite often (say you have 5 devices) a movie will be encrypted in such a 
way that any of the 5 keys will decrypt the message, OR the content is 
available for download and will be encrypted with 1 key (for the target 
device), but the server will only allow up to 5 target devices.

Effectively two options:
a) 1 file - decryptable on any of the 5 devices,
b) 5 files (actually 1 file encrypted on the fly during download) - only 
decryptable on a single target device device.

IT IS ABSOLUTELY NOT 'DOWN TO TRUST' that you'll not keep the file. They 
don't care as it's useless to use unless you can decrypt it.


Screen grabbers and audio interception are techniques that can allow the 
media to be copied (just as you could use a camcorder on your screen!), 
but these would normally not be bit perfect copies (audio streams 
sometimes are).
Some technologies, like Silverlight, made it particularly difficult to 
'intercept' the video and audio between the decryption and video 
playback processes.

in the old days Windows Media DRM was broken (because the decryption 
keys were held in RAM and could be found after WMP had terminated) - 
this meant that stored video on your hard drive could be decrypted and 
this DRM was defeated. That's (in part) why Microsoft developed 
Silverlight which was never cracked.


When it comes to VMWare, people still need a license to run a VM with a 
commercial operating system. So, if you run Windows in a VM, you have to 
buy Windows.

A VPN is entirely different, it's merely a 'tunnel' that masks your IP 
activity. In turn a VPN usually connects to a proxy in another country, 
thus giving the impression you're located in the same country as the 
proxy. One of the benefits of this, is that you can 'deceive' content 
providers and gain access to their content.
The reasons they limit access to their content is almost always 
licensing. The BBC will have negotiated rights to offer a TV series or 
Movie to the UK market only for a period of 1 month (say). That same 
content might be available to a French broadcaster in France for 2 
months (depending on the fees they paid for the content).  If either the 
BBC or the French Broadcaster are found to be leaking content in high 
volume to (say) Spain, then it's losing the content owner money in Spain!