Re: RNG in a Smart Card

Bruce Schneier (schneier@counterpane.com)
Thu, 16 Jul 1998 11:32:09 -0500

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At 11:15 PM 7/16/98 +0800, Ng Pheng Siong wrote:
>Hi,
>
>(Attempting to draw another thread on randomness...)
>
>Some smart cards, like Schlumberger's CryptoFlex, can generate keys
>within the card. (Which others?)
>
>The question is: how does a smart card harvest entropy to generate "good"
>random numbers? There aren't UI events, network packets, etc.
>
>If the entropy comes from sampling electrical noise, or whatever, what does
>physics tell us about the constraints on parameters like sampling rate,
>quantifying entropy, etc., in the context of operating within a smart card?

My guess is that they use a very breakable random number generator.

Bruce
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