Re: data diodes

From: Ed Kennedy <ekennedyx_at_yahoo_dot_com>
Date: Sun Dec 03 2006 - 21:42:23 CST


        About Luddites: I tend to follow the 7/8ths rule. If I can
convince approximately that many people, I usually just ignore the remaining



Edmund R. Kennedy, PE
10777 Bendigo Cove
San Diego, CA 92126

-----Original Message-----
[] On Behalf
Of Cameron L. Spitzer
Sent: Sunday, December 03, 2006 10:50 AM
Subject: Re: [OVC-discuss] data diodes

First off, bravo for data diodes. It's an elegant little design.
I'd be careful overselling it, though. The receiver is powered
off two handshake signals, so it's not going to work connected to
just any "RS-232" serial port. "RS-232" isn't enforced the way
Ethernet is, and it's common to find the output resistance and
voltages fall *way* short of the old EIA spec. I designed an
opto-isolated "RS-232" for a high end router once, and it was
surprisingly tricky to get it to tolerate real-world "RS-232".

>From: "Ed Kennedy" <>
>Date: Sat, 2 Dec 2006 13:29:18 -0800
>Subject: Re: [OVC-discuss] data diodes

>Hello Charlie:

> The problem is simply a one of confidence. The devices you propose
>are probably very efficient and trouble free. However, one needs to be
>to take a pointer to the device and say, "See that little thing there?

Hmm, you'll never convince the real luddites. If it's electronic,
they believe it can have bad guy magic in it.

>[From]: Charlie Strauss
>Sent: Friday, December 01, 2006 8:29 PM
>To: Open Voting Consortium discussion list
>Subject: [OVC-discuss] data diodes

>Specifically, monolithic chips that perform this function have been
>available since the 70's. They go by many names, vactrols,
>optoswitches, optical isolators...

Those aren't monolithic. There are two chips in those
little packages, separated by transparent glass or plastic.
Multi-thousand-volt isolation on a single chip is impractical.


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Received on Sun Dec 31 23:17:04 2006

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