Encrypting Pagers is Easy! [Overview, technical tradeoffs, crypto]

Gold Dot golddot at nym.alias.net
Wed Oct 1 19:44:00 PDT 1997



Y'all:

Since I design pagers for a living, I thought I might comment
on encryption in pagers.

I've been thinking about encryption in pagers for several years
now.  RC4 was suggested, and it is probably a good choice for the 
low end microcontrollers used in pagers.

The problem with encryption in pagers is not algorithms, hardware, 
software or even technology.  The problem is getting awareness 
that there is a problem transmitting pages in the clear.  Most 
people have no clue and I've seen not one request from a customer 
(meaning large paging companies) for encrypted pagers.  A few 
more well-publisized hacks will help, though.  Code space is at
a premium in a pager, so widespread awareness of the inherent
insecurity of paging protocols will be necessary to get encryption
into the products.

So, here's a project for any hacker with time on their hands.
Input the audio signal from a garden variety scanner into your
sound card (just about any variety will do) and decode the 
signal.  It's just 4 level FM.  I'd do it myself, but I value
my job. :-)

Or, if you're lazy and have money, buy yourself a SignalPro and
decode two channels simulaneously.

Then, scan paging systems in strategic locations and post the
juicy tidbits to the 'net.

TTFN,

Gold Dot
golddot at nym.alias.net
"Gold is money, and nothing else is." -- some dead guy







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