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- Newsgroups: sci.crypt
- Path: sparky!uunet!utcsri!torn!nott!cunews!csi.uottawa.ca!news
- From: cbbrowne@csi.uottawa.ca (Christopher Browne)
- Subject: Re: A new encryption problem?
- Message-ID: <1992Nov6.213007.6500@csi.uottawa.ca>
- Sender: news@csi.uottawa.ca
- Nntp-Posting-Host: prgv
- Organization: Dept. of Computer Science, University of Ottawa
- References: <lfjmkiINNa74@exodus.Eng.Sun.COM> <7986@transfer.stratus.com>
- Date: Fri, 6 Nov 92 21:30:07 GMT
- Lines: 29
-
- In article <7986@transfer.stratus.com> cme@ellisun.sw.stratus.com (Carl Ellison) writes:
- >In article <lfjmkiINNa74@exodus.Eng.Sun.COM> silber@orfeo.Eng.Sun.COM (Eric Silber) writes:
- >> Require: (for-all p)( (c=E(p)) is a text which appears to be
- >> a plaintext)
- >
- >
- >The problem here is that both c and p must carry information and be
- >believable both in style and as a real communication. ("The pen of my aunt
- >is on the table" doesn't pass as a real communication even though it parses
- >correctly.)
-
- The only "obvious" way around this is to use "steganography", where
- through some (seemingly minor) changes in a cover message, you communicate
- the "real" message. Maybe through extra spaces here and there; maybe in
- some sort of line break pattern; probably generically through some use
- of "punctuation" in a message.
-
- It makes data compression all the more important - if you can compress
- the REAL message to 1/3 the size, there's only 1/3 as much "steganoizing"
- to do, which is REALLY important, because this sort of scheme would
- require a LOT of cover text.
-
- And to avoid spoofing? Might want to send an MD5 checksum via some other
- channel...
- --
- Christopher Browne | PGP 2.0 key available
- cbbrowne@csi.uottawa.ca |===================================
- University of Ottawa | The Personal Computer: Colt 45
- Master of System Science Program | of the Information Frontier
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