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- Newsgroups: sci.crypt
- Path: sparky!uunet!caen!malgudi.oar.net!chemabs!jac54
- From: jac54@cas.org ()
- Subject: Re: transposition ciphers
- Message-ID: <1992Jul27.111322.8987@cas.org>
- Keywords: cipher transposition multiple anagram broken US civil war
- Sender: usenet@cas.org
- Organization: Chemical Abstracts Service, Columbus, Ohio
- References: <92207.142318U27239@uicvm.uic.edu> <1992Jul26.074121.15669@chpc.utexas.edu>
- Date: Mon, 27 Jul 1992 11:13:22 GMT
- Lines: 23
-
- In article <1992Jul26.074121.15669@chpc.utexas.edu> jonathan@chpc.utexas.edu (Jonathan Thornburg) writes:
- >In article <92207.142318U27239@uicvm.uic.edu> Gerald Strom
- ><U27239@uicvm.uic.edu> writes:
- >>The following is a little piece I wrote recently about transposition
- >>ciphers. As I am far from being an expert in this field, I hope I
- >>didn't get too much wrong and I would appreciate comments.
- >> [description and C code deleted]
- >
- >Shouldn't you also point out that any transposition cipher can be
- >broken by multiple anagramming? Kahn "The Codebreakers" discusses
- >this and gives a couple of examples of broken transposition ciphers,
- >I believe dating back to the US civil war and the 1884 (?) US
- >presidential election.
- >
- Doesn't this only work with a route and/or block transpositions?
- When a transposition using a randomized mapping (transposition
- sites randomly assigned) it becomes much more difficult,
- especially if your map is a one-time pad. Incidentally, there
- are only about 40 systematic routes through a 5x5 transposition
- block. I tried working them out once, it's very character-
- building.
-
- Alec Chambers.
-