>>>>>>>If all this function does is encrypt a password there are lots of examples written in c# out there ( Google is your friend )
>>>>>>
>>>>>>I did but so for I could not find a simple enough c# encrypt function that can be "duplicated" in VFP. You see I need a function that would do the same from VFP and c# end.
>>>>>>Thank you.
>>>>>
>>>>>Presumably you mean that the C# version should be usable with strings already encoded using the VFP cipher library that you mentioned?
>>>>>
>>>>>Al's pointer to Rick's paper is still valid - you could create a small VFP com interop which could be accessed from .net.
>>>>>
>>>>>But which functions of that library do you actually use ? - the core encryption is fairly straightforward.
>>>>>I took a look at the original C code and it would seem that a C# version should be simple enough to implement......
>>>>
>>>>The function cipher() I am using in VFP code is written in VFP; not in C. Maybe Sergey also wrote it in C but the one he recommended to me years ago was the VFP function. To be honest, I don't even understand all VFP functions he used in creating the cipher(). So converting/rewriting it to C# would be a great challenge.
>>>
>>>The VFP code was based on a C conversion and there's a link to the C source - you might find that easier to convert to C# (or not :-} )
>>
>>Do you know where I can find the DLL (I presume tha the C code was built into a DLL) file that uses this C code? And maybe it has the C code there as well.
>
>Does this work (not properly tested and could certainly be improved):

using System;
>using System.Linq;
>using System.Text;
>
>namespace Cipher
>{
>    public class Cipher
>    {
>        private const int PwMinNum = 1000;
>
>        public string Encrypt(string tcStr, string tcPassword)
>        {
>            byte[] tcStrBytes = Encoding.ASCII.GetBytes(tcStr);
>            int tcStrLength = tcStrBytes.Length;
>
>            string lcPassword = tcPassword + '0';
>            byte[] lcPasswordBytes = Encoding.ASCII.GetBytes(lcPassword);
>            int lnPassLen = lcPasswordBytes.Length - 1;
>
>            int lnPassPos = 0;
> 
>            string lcStrOut = string.Empty;
>
>            int lnPassNum = ((CipherGetPnum(lcPassword)/997 - 1)%254) + 1;
>            
>            for (int i = 0; i < tcStrLength;i++)
>            {
>                int lnNum01 = ((lnPassNum + (i - tcStrLength)) - 1);
>                lnPassNum = (Math.Abs(lnNum01)%254)*Math.Sign(lnNum01) + 1;
>                var lnByte = tcStrBytes[i] ^ (lnPassNum ^ lcPasswordBytes[lnPassPos]);
>                lnByte = lnByte & 0xFF;
>                lcStrOut = lcStrOut + (lnByte == 0 ? Convert.ToChar( tcStrBytes[i + 1]) : Convert.ToChar(lnByte));
>                lnPassPos = lnPassPos>=lnPassLen ? 1:lnPassPos + 1;
>            }
>            return lcStrOut;
>        }
>
>        private int CipherGetPnum(string tcStr)
>        {
>            byte[] ascii = Encoding.ASCII.GetBytes(tcStr);
>            int liRet = 1 + ascii.Select((t, i) => t + i).Sum();
>
>            while (liRet < PwMinNum)
>            {
>                liRet = liRet << 1;
>            }
>            return liRet;
>        }
>    }
>}

Thank you for the code. As I just mentioned in my reply to myself that I found the code that I did about 6 months ago. I will compare my code to your code. I take my hat off to you as you have done it in less than an hour and I remember it took me at least 2 days to write my C# code (and million of Google searches). Thank you!