Re: Random Data from Geiger Counter

Enzo Michelangeli (em@who.net)
Fri, 10 Jul 1998 10:34:59 +0800

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By the way: radioactive decay may be a tough not to crack, but a
Geiger-based RNG could also be influenced by injecting large EM pulses in
the electronics AFTER the tube, especially in the analog amplifier circuitry
before the Schmitt trigger: and this doesn't make it much better than a RNG
based on Zener diodes and such. As it often happens in crypto, a RNG chain
is only as strong as its weakest link...

Enzo

-----Original Message-----
From: bill.stewart@pobox.com <bill.stewart@pobox.com>
To: CodherPlunks@toad.com <CodherPlunks@toad.com>
Cc: CodherPlunks@toad.com <CodherPlunks@toad.com>
Date: Wednesday, July 08, 1998 1:53 AM
Subject: Re: Random Data from Geiger Counter

>>>I'm not convinced this is true: I can't influence the way a sample
>>>decays, but surely I can inject my own alpha/beta/gamma particles into
>>>the system at predictable moments? I'm not saying this is cheap or easy,
>>>but surely possible.
>>
>>This would be essentially impossible to do without being detected, because
>>the equipment needed to do so would have to be both large and near the

>>detector. Not only that, but it would be essentially impossible to

>
>The folks who run a large radioactivity source about 93 million miles away
>might disagree on the need for nearness, though their source is
>relatively detectable :-)
>
>Unless your target has a physically secure environment,
>which most people's houses and laboratories aren't, it doesn't take
>a cyclotron to add some extra radioactivity near the detector,
>just a bit of radioactive material. If you can't blackbag a radioactive
>source into the detector itself, you can send radioactive paper mail,
whether
>junk mail for the wastebasket or free samples of yellow sticky notes.
>
>Of course, if you've got physical access to the system, there are
>all sorts of Bad Things you can do that are simpler than injecting
>radioactivity into the system, though perhaps harder to detect.
>
>
> Thanks!
> Bill
>Bill Stewart, bill.stewart@pobox.com
>PGP Fingerprint D454 E202 CBC8 40BF 3C85 B884 0ABE 4639
>

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