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| From | Richard Heathfield <rjh@cpax.org.uk> |
|---|---|
| Newsgroups | comp.lang.c |
| Subject | Re: Program to cipher a text, new thread, fresh one |
| Date | 2015-11-02 13:48 +0000 |
| Organization | A noiseless patient Spider |
| Message-ID | <n17pfa$2lr$1@dont-email.me> (permalink) |
| References | <8465675b-8538-4031-a5b7-d5ddba34197d@googlegroups.com> <d9hlo7F4tr6U1@mid.individual.net> <n14o50$qqb$1@dont-email.me> <318982b5-b8e6-4cfc-ad08-79cc99a2b162@googlegroups.com> |
On 01/11/15 15:59, supercat@casperkitty.com wrote: > On Sunday, November 1, 2015 at 4:07:44 AM UTC-6, Richard Heathfield wrote: >> I can easily imagine the Vigenere cipher's original users being >> case-blind - that is, not actually making any distinction between upper >> and lower case either in the keyword or in the message text. I can >> equally imagine them skipping punctuation - that is, duplicating it >> without consuming key material. > > From what I understand, common cryptographic practice was to strip out all > punctuation and word spaces, see if the message made sense, if it didn't > either rewrite it and/or add some obvious "noise characters" like Q or X > to imply word breaks, then encipher the message and add word breaks at > regular intervals. Preserving original word spaces and punctuation would > give excessively strong clues as to the message content, which could not > only assist in deciphering it, but could even allow the enemy to glean > information *without* deciphering it. Whether most users would have been that cautious, knowing as they did that the cipher was unbreakable, is probably an open question. One thing that is not an open question, though, is the fact that Vigenere has been broken, and no sensible person relies on it for security nowadays. Therefore, we may safely assume that any Vigenere program written today is for educational (or home entertainment) purposes, and we therefore don't have to get too snarled up on the details. -- Richard Heathfield Email: rjh at cpax dot org dot uk "Usenet is a strange place" - dmr 29 July 1999 Sig line 4 vacant - apply within
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Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 08:23 -0700
Re: Program to cipher a text, new thread, fresh one Bartc <bc@freeuk.com> - 2015-10-30 15:39 +0000
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 09:33 -0700
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-01 09:33 +0000
Re: Program to cipher a text, new thread, fresh one Mark Storkamp <mstorkamp@yahoo.com> - 2015-10-30 11:17 -0500
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 09:32 -0700
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-01 09:38 +0000
Re: Program to cipher a text, new thread, fresh one "Osmium" <r124c4u102@comcast.net> - 2015-10-30 10:55 -0600
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-01 10:07 +0000
Re: Program to cipher a text, new thread, fresh one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-01 10:42 +0000
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-01 11:35 +0000
Re: Program to cipher a text, new thread, fresh one James Kuyper <jameskuyper@verizon.net> - 2015-11-01 08:33 -0500
Re: Program to cipher a text, new thread, fresh one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-01 16:09 +0000
Re: Program to cipher a text, new thread, fresh one Bartc <bc@freeuk.com> - 2015-11-02 12:43 +0000
Re: Program to cipher a text, new thread, fresh one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-11-02 13:25 +0000
Re: Program to cipher a text, new thread, fresh one Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-11-02 06:13 -0800
Re: Program to cipher a text, new thread, fresh one Keith Thompson <kst-u@mib.org> - 2015-11-01 12:26 -0800
Re: Program to cipher a text, new thread, fresh one supercat@casperkitty.com - 2015-11-01 07:59 -0800
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-02 13:48 +0000
Re: Program to cipher a text, new thread, fresh one Bartc <bc@freeuk.com> - 2015-11-02 14:06 +0000
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-02 14:51 +0000
Re: Program to cipher a text, new thread, fresh one Bartc <bc@freeuk.com> - 2015-11-02 15:48 +0000
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-02 16:00 +0000
Re: Program to cipher a text, new thread, fresh one asetofsymbols@gmail.com - 2015-11-03 01:40 -0800
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-03 11:16 +0000
Re: Program to cipher a text, new thread, fresh one "Osmium" <r124c4u102@comcast.net> - 2015-11-03 05:21 -0600
Re: Program to cipher a text, new thread, fresh one asetofsymbols@gmail.com - 2015-11-03 03:41 -0800
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-03 11:53 +0000
Re: Program to cipher a text, new thread, fresh one "Osmium" <r124c4u102@comcast.net> - 2015-11-03 05:57 -0600
Re: Program to cipher a text, new thread, fresh one Richard Heathfield <rjh@cpax.org.uk> - 2015-11-03 12:48 +0000
Re: Program to cipher a text, new thread, fresh one Rosario19 <Ros@invalid.invalid> - 2015-11-04 09:09 +0100
Re: Program to cipher a text, new thread, fresh one Rosario19 <Ros@invalid.invalid> - 2015-11-04 09:37 +0100
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-11-04 07:09 -0800
Re: Program to cipher a text, new thread, fresh one "Osmium" <r124c4u102@comcast.net> - 2015-11-03 05:53 -0600
Re: Program to cipher a text, new thread, fresh one asetofsymbols@gmail.com - 2015-11-03 04:29 -0800
Re: Program to cipher a text, new thread, fresh one "Osmium" <r124c4u102@comcast.net> - 2015-11-03 06:42 -0600
Re: Program to cipher a text, new thread, fresh one Geoff <geoff@invalid.invalid> - 2015-11-01 08:07 -0800
Re: Program to cipher a text, new thread, fresh one Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-02 02:26 -0800
Re: Program to cipher a text, new thread, fresh one Rosario19 <Ros@invalid.invalid> - 2015-11-06 07:53 +0100
Re: Program to cipher a text, new thread, fresh one Tim Rentsch <txr@alumni.caltech.edu> - 2015-11-07 10:01 -0800
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 10:50 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 10:53 -0700
Re: Program to cipher a text, new thread, fresh one Barry Schwarz <schwarzb@dqel.com> - 2015-10-30 11:52 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 12:12 -0700
Re: Program to cipher a text, new thread, fresh one Barry Schwarz <schwarzb@dqel.com> - 2015-10-30 21:05 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 23:58 -0700
Re: Program to cipher a text, new thread, fresh one Barry Schwarz <schwarzb@dqel.com> - 2015-10-31 03:09 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-31 03:47 -0700
Re: Program to cipher a text, new thread, fresh one Barry Schwarz <schwarzb@dqel.com> - 2015-10-31 11:42 -0700
Re: Program to cipher a text, new thread, fresh one Barry Schwarz <schwarzb@dqel.com> - 2015-10-30 12:04 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 12:10 -0700
Re: Program to cipher a text, new thread, fresh one "Osmium" <r124c4u102@comcast.net> - 2015-10-30 13:17 -0600
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-31 00:04 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-31 00:25 -0700
Re: Program to cipher a text, new thread, fresh one Keith Thompson <kst-u@mib.org> - 2015-10-30 12:34 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-30 21:49 -0700
Re: Program to cipher a text, new thread, fresh one Keith Thompson <kst-u@mib.org> - 2015-10-31 13:18 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-31 00:29 -0700
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-31 01:12 -0700
Re: Program to cipher a text, new thread, fresh one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-31 12:24 +0000
Re: Program to cipher a text, new thread, fresh one Alla _ <modelling.data@gmail.com> - 2015-10-31 06:11 -0700
Re: Program to cipher a text, new thread, fresh one Bartc <bc@freeuk.com> - 2015-10-31 15:58 +0000
Re: Program to cipher a text, new thread, fresh one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-31 17:37 +0000
Re: Program to cipher a text, new thread, fresh one Bartc <bc@freeuk.com> - 2015-10-31 18:14 +0000
Re: Program to cipher a text, new thread, fresh one Keith Thompson <kst-u@mib.org> - 2015-10-31 13:29 -0700
Re: Program to cipher a text, new thread, fresh one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-31 20:35 +0000
Re: Program to cipher a text, new thread, fresh one Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-10-31 20:32 +0000
Re: Program to cipher a text, new thread, fresh one Rosario19 <Ros@invalid.invalid> - 2015-11-04 09:50 +0100
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