Нужен совет об увеличении безопасности VB-шного приложения

Private Const thisString = '-- здесь достаточно длинная строка (у меня 86) из любых символов --'
Private thisStart As Variant
 
Private Sub Form_Load()
  thisStart = Array(52, 25, 43, 67, 28, 16, 49, 46, 4, 61, 31, 34, 19, 10, 64, 37, 58, 7, 1, 40, 55, 13)
End Sub
 
 
Private Function Encrypt(yourString As String) As String
  Dim myIndex As Integer, myOffset As Integer
  Dim myChar As Integer, myLeft As Integer, myRight As Integer
 
  myOffset = (Len(yourString) * 2) Mod 22
  For myIndex = 1 To Len(yourString)
    myChar = Asc(Mid(yourString, myIndex, 1))
    myRight = myChar And 7
    myLeft = myChar  8
    Encrypt = Encrypt & Mid(thisString, myLeft + thisStart(myOffset), 1) & Mid(thisString, myRight + thisStart(myOffset + 1), 1)
    myOffset = (myOffset + 2) Mod 22
  Next myIndex
End Function
 
Private Function Decrypt(yourString As String) As String
  Dim myIndex As Integer, myOffset As Integer
  Dim myChar As Integer, myLeft As Integer, myRight As Integer
  
  If (Len(yourString) Mod 2) Then
    Err.Raise 541, 'Decrypt', 'Invalid Password'
  End If
 
  myOffset = Len(yourString) Mod 22
  For myIndex = 1 To Len(yourString) Step 2
    myLeft = InStr(Mid(thisString, thisStart(myOffset), 16), Mid(yourString, myIndex, 1)) - 1
    myRight = InStr(Mid(thisString, thisStart(myOffset + 1), 16), Mid(yourString, myIndex + 1, 1)) - 1
    If (myLeft < 0) Or (myRight < 0) Then
      Err.Raise 541, 'Decrypt', 'Invalid Password'
    End If
    myChar = (myLeft * 8) Or myRight
    Decrypt = Decrypt & Chr(myChar)
    myOffset = (myOffset + 2) Mod 22
  Next myIndex
End Function