[cryptography] [liberationtech] Heml.is - "The Beautiful & Secure Messenger"

coderman coderman at gmail.com
Tue Jul 16 05:04:09 EDT 2013


On Mon, Jul 15, 2013 at 8:39 AM, The Doctor <drwho at virtadpt.net> wrote:
> ...
> Why hire ninjas to backdoor a chip when you can have someone look for
> 0-days?  Cheaper and emminently practical.  Oh, and already being done.

these are complimentary methods. for some targets you may not care
about stealth, or visible breakage, or active methods. 0wn their apps,
OS, network devices, whatever soft targets for great success.

sometimes you need stealth and longevity; a weakened key space
sufficient to attack with modest hardware (c.f. NSA Utah ;) could go
undetected for years, if ever noticed.

all cursory checks show encryption functional, side channels
squelched, implementation operational - and yet, here you are using
long lived public keys, symmetric session keys, and other secrets with
insufficient entropy.

  result: all your security is null and all your content in the hands
of the adversary.

---

consider the focus on baseband attacks for mobile. is it easier to own
the application or OS layers? absolutely.  but this is also
potentially mitigated by fine grained access controls, custom ROMs,
many various techniques in these same application and OS layers.

a baseband exploit cares nothing for the OS and application layer
details, instead providing direct access to device memory and
interfaces surreptitiously for keys in memory and content on device.
  even airplane mode can be hacked into open mic night while the user
is none the wiser!

baseband attacks are much more complicated, device specific, and
expensive (for some measure of cost) compared to the easier and more
plentiful application and OS layer hacks on android and iOS, but this
cost is justified by the significant improvement in capability,
stealth, and reliability.

---

in short:

rather than considering just one or another type of attack, these
agencies should be assumed to be using all of them with the exploit
method tailored to the particular access needs and target difficulty
of every tasking.


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