[Meego-tv] White paper Security requirement for TV under MeeGo

[Rudolf Streif]

This whitepaper is a good start and the cases of booting the STB, signing
bootloaders, development and user mode, protection of the content assets,
protection of the security subsystem, etc are very well covered from the
view of a traditional TV use case model. Yes, it touches on (third-party)
applications but it does not touch on how these applications will interact
with each other to enable new use cases which are desired by the operators
as well as the consumers. However, these interactions could open new
vulnerabilities.

Some examples:

A common use case will be that the actual and potentially protected content
will not consume the entire screen but will share the screen with other
applications let's say a web browser, a Facebook client etc. This means
protected video will be overlaid, tiled, mixed etc. with unprotected content
during rendition for output through digital (mostly) and/or analog
(shrinking) video interfaces. The way how this is done can potentially
create security loopholes allowing descrambled and decoded content to be
siphoned off.

Local transcryption of content with keys derived from a hardware key ladder
etc. was described in the paper. A use case of an STB could allow users to
store their own content such as photos or home videos on the STB. While
users will typically not want to encrypt their own content a loophole in the
architecture may accidentally allow them to do so. This could be exploited
for so-called "known clear message pattern" attacks etc. (As a side note:
the cipher alone e.g. AES128 does not guarantee the strength of the
solution; equal attention needs to be paid to what cipher mode e.g. ECB,
CBC, CFB etc. is used)

It is very hard to anticipate potential vulnerabilities. And with the may
new use cases for SmartTV will offer over the traditional TV consumption
model it becomes very important to closely look at use cases and interaction
themselves to identify the risks.

Rudi


2011/3/22 Dominig Ar Foll <dominig.arfoll at fridu.net>

> Hello,
>
> just wanted to let you know that a MeeGo and TV security whitepaper that I
> wrote a few months ago has gone public.
> You can find it on Amino web site. It was written before the recent changes
> in the security framework coming with MeeGo 1.2, but the described use cases
> remain valid.
>
> http://www.aminocom.com/what-we-offer/amino-and-meego/
>
> (FYI same post has been done on the security-discussion mailing list)
> --
> Dominig ar Foll
> MeeGo TV
> Intel Open Source Technology Centre
>
>
> _______________________________________________
> MeeGo-tv mailing list
> MeeGo-tv at lists.meego.com
> http://lists.meego.com/listinfo/meego-tv
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.meego.com/pipermail/meego-tv/attachments/20110323/212d94b7/attachment.html>