Private Function STR_TO_ARRAY(Str As String) As String()
    Dim tmpArray() As String

    ReDim tmpArray(0 To Len(Str))
   
    For i = 0 To Len(Str)
        tmpArray(i) = Mid(Str, InStr(Str, Str) + i, 1)
    Next i
STR_TO_ARRAY = tmpArray
End Function

Private Function ARRAY_TO_STR(Str() As String) As String
    Dim tmpArray() As String
    Dim tmpStr As String
   
    ReDim tmpArray(LBound(Str) To UBound(Str))
    tmpArray = Str
    For i = LBound(Str) To UBound(Str)
        If i = LBound(Str) Then
            tmpStr = tmpArray(i)
        Else
            tmpStr = tmpStr & tmpArray(i)
        End If
    Next i
ARRAY_TO_STR = tmpStr
End Function

Private Function ARRAY_TO_ASC(Str() As String) As String()
    Dim tmpArray() As String
    Dim tmpAsc() As String
   
    ReDim tmpArray(LBound(Str) To UBound(Str))
    ReDim tmpAsc(LBound(Str) To UBound(Str))
   
    tmpArray = Str
    For i = LBound(Str) To (UBound(Str) - 1)
        tmpAsc(i) = Asc(tmpArray(i))
    Next i
ARRAY_TO_ASC = tmpAsc
End Function

Private Function Encrypt(Str As String) As String
    Dim tmpArray() As String
    Dim tmpAsc() As String
    Dim tmpFin As String
   
    tmpArray() = STR_TO_ARRAY(Str)
    tmpAsc() = ARRAY_TO_ASC(tmpArray())
   
    For i = LBound(tmpAsc()) To (UBound(tmpAsc()) - 1)
        If i = LBound(tmpAsc()) Then
            tmpFin = Chr(tmpAsc(i) - 1)
        Else
            tmpFin = tmpFin & Chr((tmpAsc(i) - 1))
        End If
    Next i
Encrypt = tmpFin
End Function

Private Function Decrypt(Str As String) As String
    Dim tmpArray() As String
    Dim tmpAsc() As String
    Dim tmpFin As String
   
    tmpArray() = STR_TO_ARRAY(Str)
    tmpAsc() = ARRAY_TO_ASC(tmpArray())
   
    For i = LBound(tmpAsc()) To (UBound(tmpAsc()) - 1)
        If i = LBound(tmpAsc()) Then
            tmpFin = Chr(tmpAsc(i) + 1)
        Else
            tmpFin = tmpFin & Chr((tmpAsc(i) + 1))
        End If
    Next i
Decrypt = tmpFin
End Function