How To Encrypt FoxPro .DBF Files

• Microsoft Visual FoxPro for Windows, version 3.0
• 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

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