Dave Emery wrote:
>       And much of the worlds wireless phone plant is GSM, which is
> almost always encrypted, which must add significantly to NSAs burden
> intercepting it, even if they can break keys very quickly...

Being rather familiar with GSM crypto, allow me to say this: most GSM voice
traffic globally is encrypted using A5/2. We know how to break A5/2 in five
clock cycles on an ASIC. For an agency that operates interception satellites
costing USD 1.5 billion each featuring antennas over twice the size of a
football field, adding 5 lousy clock cycles for the cryptanalysis to the
many clock cycles required to demodulate a GSM call can not be considered to
be significant. Immaterial would be a better term.

A5/1 likely requires more clock cycles. How many clock cycles we don't know
and won't know until the cryptographic community takes a serious look at
A5/1. But I from what I know about A5/1, it won't be a showstopper by any

I know how to build a GSM interception station using off-the-shelf hardware
and a PII running Linux for a total cost of well below USD 10k. Give me a
couple of billions of dollars, peanuts for the NSA, and I hereby guarantee
you that I can take that system down to a single chip and some RF hardware.

--Lucky Green <[EMAIL PROTECTED]>

  "Among the many misdeeds of British rule in India, history will look
   upon the Act depriving a whole nation of arms as the blackest."
  - Mohandas K. Gandhi, An Autobiography, pg 446

Reply via email to