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From: jloup@chorus.fr (Jean-loup Gailly)
Newsgroups: comp.sources.misc
Subject: v31i128: zcrypt19 - Info-zip portable zip/unzip (encryption code), Part01/01
Message-ID: <1992Aug28.130023.10695@aber.ac.uk>
Date: 28 Aug 92 13:00:23 GMT
Sender: aem@aber.ac.uk (Alec David Muffett)
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Organization: University College of Wales, Aberystwyth
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Submitted-by: Jean-loup Gailly <jloup@chorus.fr>
Posting-number: Volume 31, Issue 128
Archive-name: zcrypt19/part01
Environment: UNIX, VMS, MS-DOS, OS/2

The files described below contain the encryption code for zip 1.9 and
unzip 5.0.  They constitute only an add-on to the exportable versions
(generally named zip19.zip or zip19.tar.Z, and unzip50.tar.Z)
and cannot be used without the complete zip package.

The encryption code is a direct transcription of the algorithm from
Roger Schlafly, described by Phil Katz in the file appnote.txt. This
file is distributed with the PKZIP program (even in the version
without encryption capabilities). Note that the encryption will
probably resist attacks by amateurs if the password is well chosen and
long enough (at least 8 characters) but it will probably not resist
attacks by experts.  Short passwords consisting of lower case letters
only can be recovered in a few hours on any workstation. But for casual
cryptography designed to keep your mother from reading your mail, it's
OK.

All bug reports should go to zip-bugs@cs.ucla.edu, and suggestions for
new features can be sent to info-zip@cs.ucla.edu.

Jean-loup Gailly
jloup@chorus.fr