Hi John,

>May I know where could I have .NET compatible VFP library? In other words, the data encrypted in VFP app can be decrypted in .NET.

The Windows Crypto API is the part of Windows that is meant for encrypting data. The .NET encryption classes call the Crypto API behind the scenes. From VFP you can use _Crypt.VCX which is located in the FFC directory of VFP.

All you have to do is to ensure that your VFP application uses the same algorithm as the .NET application expects. Also, you should make sure that encrypted content is not somehow converted due to code page changes, Unicode gateways, etc.

For Windows Vista, Server 2008 and Windows 7 there's also the Cryptography API: Next Generation, or CNG for short, which feature elliptic encryption and asymmetric algorithms.