For large files, you might also want to take a look of the following paper Krawczyk, H. Secret sharing made short. In Advances in Cryptology -- Crypto '93. pages 136-146
See also HAC pages 539. Steve -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Wednesday, July 16, 2003 11:59 AM To: [EMAIL PROTECTED] Subject: Looking for an N -out-of-M split algorithm Hi, I remember reading (many years ago) a description on some web page somewhere of an algorithm by which an arbitrary file F could be split into M pieces, such that: (1) given any N pieces, F can be reconstructed precisely, and (2) given fewer than N pieces, it is impossible to determine even a single bit of information about F. Unfortunately, that was many years ago, and -- search as I might -- I haven't been able to find it on web now. Does anyone have any idea where I might learn about this algorithm - or indeed any algorithm which does the job. Jill [Moderator's note: look for "Shamir Sharing" -- the trick is just turning the secret into a polynomial of degree N so that with enough points you determine the polynomial uniquely and with too few you can't determine it. I'm pretty sure that Schneier and all of the other standard references explain this trick. --Perry] --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED] --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]
