Fwd: Shamir secret sharing and information theoretic security

20 Feb 2009


      Begin forwarded message:
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From: Jonathan Katz <jkatz@cs.umd.edu>
Date: February 20, 2009 12:34:31 PM EST
To: "R.A. Hettinga" <rah@shipwright.com>
Cc: Cryptography <cryptography@metzdowd.com>
Subject: Re: Shamir secret sharing and information theoretic security
On Tue, 17 Feb 2009, R.A. Hettinga wrote:
...
hi,
I was going through the wikipedia example of shamir secret sharing  
which says it is information theoretically secure.
http://en.wikipedia.org/wiki/Shamir%27s_Secret_Sharing
...
The scheme is defined over a finite field *not* over the integers.  
When Shamir's scheme is run over a finite field, it is information  
theoretically secure.