Unfortunately I cannot reproduce this using your applet. The data is correctly encrypted and decrypted using 0 and the values you provided for the low and high keys.
I wonder if using the Clipboard is a factor. Here is the code I used to test the method, which uses a MsgBox to outout values. I would be interested to see if this works for you:
Sub Main(Client, GWEvent) dim aPlain dim iHighKey dim iLowKey sPlain = "this is just an example" iHighKey = 145 iLowKey = 1234 sEncrypt = utilities.DESEncryption(fEncrypt, iHighKey, iLowKey, sPlain) sDecrypt = utilities.DESEncryption(fDecrypt, iHighKey, iLowKey, sEncrypt) MsgBox("sPlain = " & sPlain & vbCrLf & "sEncrypt = " & sEncrypt & vbCrLf & "sDecrypt = " & sDecrypt & vbCrLf) End Sub