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From: bsy+@CS.CMU.EDU (Bennet Yee)
Subject: Re: Why public domain encryption software may not be good enough.
Message-ID: <1992Jan31.201635.32511@cs.cmu.edu>
Date: Fri, 31 Jan 92 20:16:35 GMT
Organization: Cranberry Melon, School of Cucumber Science
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In article <10746@lectroid.sw.stratus.com>, cme@ellisun.sw.stratus.com (Carl Ellison) writes:
>This is addressed quite adequately by secret sharing protocols.
>
>See Shamir's paper in CACM Nov 1979, vol 22, # 11, p 612,
>		"How to Share a Secret"
>
>It's a simple method of giving out information to N people such that any K
>of them can agree together to reconstruct the secret.
>
>So -- if you're encrypting company files, send the key out to the corporate
>officers and keep it yourself.  If you get hit by a truck, the company can
>recover its own data -- but it can't recover your torrid love letters
>to/from the president's secretary.  If on the other hand you use a
>"slightly weak" encryption system, ....

You don't have to bother people with keys.  Just encrypt the pieces of
the shared secret by the public keys of the various company officers
and keep it on your own (backed up, I hope) disk, along with the
encrypted data.  This simplifies the key management.

-bsy

-- 
Bennet S. Yee		Phone: +1 412 268-7571		Email: bsy+@cs.cmu.edu
School of Computer Science, Carnegie Mellon, Pittsburgh, PA 15213-3890
