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Q115476: How To Encrypt FoxPro .DBF Files

Article: Q115476
Product(s): Microsoft FoxPro
Version(s): 2.50 2.50a 2.50b 2.60 3.00| 2.00
Operating System(s): 
Keyword(s): kb3rdparty
Last Modified: 24-AUG-1999

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, versions 3.0, 6.0 
- Microsoft FoxPro for MS-DOS, versions 2.0, 2.5, 2.5a, 2.5b, 2.6 
- Microsoft FoxPro for Windows, versions 2.5, 2.5a, 2.5b, 2.6 
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SUMMARY
=======

FoxPro can encrypt database files by building them into an encrypted .EXE file.
However, when the .EXE file is run, the database files cannot be modified.

To work around this behavior, you can use several third-party products to encrypt
FoxPro database files while allowing the data to be modified. You can also write
a program to encrypt FoxPro database files.

MORE INFORMATION
================

Encryption prevents users from accessing .DBF files directly. It works by
changing the file so it is not recognizable as a .DBF file. FoxPro cannot use
the database file again until it is decrypted. Following are some of the ways
you can encrypt .DBF files in FoxPro.

Using FoxPro to Encrypt .DBFs
-----------------------------

If a database file does not need to be modified, you can add it to your project
list and not mark it for exclusion. When you build an encrypted .EXE file, the
.DBF data will be included in it. You do not need to physically copy the .DBF
file to the subdirectory where the .EXE file will be found. When you run the
.EXE file, the database information can be accessed but it cannot be changed.
Decryption of the .DBF file is automatic when the .EXE file is run.

Third-Party Products to Encrypt .DBFs
-------------------------------------

NOTE: The third-party products included here are manufactured by vendors
independent of Microsoft; we make no warranty, implied or otherwise, regarding
these products' performance or reliability.

  NetLib
  Communication Horizons
  65 High Ridge Road, Suite 428
  Stamford, CT 06905
  Phone: (203) 656-0448 or (800) 480-1604
  Fax: (203) 655-4049
  http://www.netlib.com
  Available for FoxPro 2.0, 2.5, and 2.6 for MS-DOS and Windows.
  A 32-bit version is scheduled to release in January 1997.
  Retails for $399.

  Cryptor
  Xitech, Inc.
  5515 Southwyck Blvd.
  Toledo, OH 43614
  Phone: (419) 867-3622
  Available for FoxPro for MS-DOS only, Windows version in development.
  Retails for $99 single user or $299 multiuser six-pack.


Writing a Program to Encrypt .DBFs
----------------------------------

Many FoxPro reference books contain sample code for different methods of
encrypting and decrypting database files.

For examples, see these books:

"FoxPro 2.0 Power Tools," Malcolm C. Rubel, pages 938-942, Bantam Books, 1991,
ISBN 0-553-35294-6

"Tom Rettig's FoxPro Handbook," Tom Rettig, pages 622-625, Bantam Books, 1990,
ISBN 0-553-34937-6

"FoxPro 2.5 Advanced Developer's Handbook", Pat Adams and Jordan Powell, pages
222-228, Brady Publishing, 1993, ISBN 0-13-325341-4

Additional query words: VFoxWin FoxDos FoxWin encrypt hide

======================================================================
Keywords          : kb3rdparty 
Technology        : kbVFPsearch kbAudDeveloper kbFoxproSearch kbZNotKeyword3 kbFoxPro200DOS kbFoxPro250DOS kbFoxPro250aDOS kbFoxPro250bDOS kbFoxPro260DOS kbFoxPro260 kbFoxPro250 kbFoxPro250a kbFoxPro250b kbVFP300 kbVFP600
Version           : 2.50 2.50a 2.50b 2.60 3.00| 2.00

=============================================================================

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