exponential relationship of crytographer and cryptanalyst

[Peter F Cassidy <pcassidy@world.std.com>]

-	I'm writing a piece on the politics of surveillance/privacy 
technologies for OMNI, essentially a survey of their advance since the 
1967 proposal for the National Data Center. I cover cryptography, 
deriving the narrative from Clipper Chip initiative. The point I'm trying 
to make is that given the market forces pushing commerce onto the public 
networks and the increasing power of available encryption, the cold war 
national apparatus will have to mobilize quickly a la digital telephony 
to stomp it - yet the nature of computing puts them in a loosing position 
in the long run. Toward the latter part of this thesis, I've been told - 
and want check with youz - of the exponential relationship of 
crytographer and cryptanalyst. The heart of this relationship has been 
explained to me as follows: Increasing the key by one bit effectively 
doubles the number of keys and proportionally increases the power 
required to break it in a brute force attack. Is this true? Is there a 
truer way of stating it? Are there complicating factors this excludes 
that I should discuss?
-				Regards,

-					Peter Cassidy