From: frantz@netcom.com (Bill Frantz)
Date: Wed, 10 Apr 1996 12:19:48 +0800
To: Steve Reid <steve@edmweb.com>
Subject: Re: Bank transactions on Internet
Message-ID: <199604091732.KAA29261@netcom9.netcom.com>
MIME-Version: 1.0
Content-Type: text/plain


At 12:13 AM 4/9/96 -0700, Steve Reid wrote:
>> Is it really that easy to break 40-bit? Don't you need access to a "fair
>> amount of cpu power" to brute force crack 40bit? 
>
>I remember reading a recent paper at this URL:
>  http://theory.lcs.mit.edu/~rivest/bsa-final-report.ascii
>They mentioned a Field Programmable Gate Array (FPGA), specifically a
>board-mounted AT&T Orca chip available for around $400. They said it could
>crack a 40-bit key in 5 hours (average). Sounds like anyone with root
>access on a major internet node could make a significant profit stealing
>credit card numbers.
>
>The FPGA sounds like a very interesting device, with quite a few
>legitimate uses... Has anyone out there seen one of these? 

I was hoping a hardware type would answer this question, and give
references to manufacture's spec sheets, but not having seen such an
answer, here is a software person's answer.

Gate arrays are a common part of complex electronics.  If you are viewing
this answer on a screen, it is quite probable that there is one right
before your nose.  They come in two basic forms, mask programmed and field
programmed.  Mask programmed gate arrays are an array of logic gates, which
are "programmed" to an application by a final metalization layer.  They are
quite inexpensive when ordered in quantity.  Field Programmed Gate Arrays
(FPGAs) are designed for prototyping designs, and can programmed
electrically.


------------------------------------------------------------------------
Bill Frantz       | The CDA means  | Periwinkle  --  Computer Consulting
(408)356-8506     | lost jobs and  | 16345 Englewood Ave.
frantz@netcom.com | dead teenagers | Los Gatos, CA 95032, USA