Frequent questions and answers for technical topics
Is your method of formula protection secure?
The DoneEx XCell Compiler compiles all formulas from xls into binary code. For nowadays this method is the most secure. Even encoding with strong encryption algorithm is not so secure because you should provide decrypt key for user and since this moment your data are decrypted and available for anybody.
I want to protect a spreadsheet file with license keys, but I don’t need to protect the formulas.
The main goal of the DoneEx XCell Compiler is a strong protection of workbook algorithms to prevent their copying. This goal is reached by compiling all workbook formulas into binary format, so after compilation there are no formulas in cells in compiled exe. Otherwise, if the formulas are not really secured protected then anyone who get permission to launch your model, (even if it was protected with password, license key and/or with hardware locking), may copy all data and formulas (manually or using some Excel AddIn) into another unprotected workbook and use your model without any restrictions.
Is it possible to extract the XLS file from the compiled EXE?
Yes, it is possible. Also you can find this file in temporary folder on you disk when compiled EXE is started.
This xls file DOESN’T contain any formulas in cells. NONE OF THEM! This file is a data provider between compiled EXE and Excel. It is used to format calculated values and to reflect them into Excel. After compilation all xls formulas are stored in EXE file (in binary, unreadable format) but not in xls. You can try this file to figure out that it doesn’t work as original xls.
Once a spreadsheet is compiled, can the user save the spreadsheet under a new name, and then use it as the newly spawned spreadsheet?
If you tie your compiled EXE file to target computer (feature of the Business Pro license) then your exe file will work on that computer only, even if it was saved with another name.
Is it possible to compile with a hardware lock and limit period usage?
You need to compile your workbook with selected “Hardware Locking” option. The date limit you will set from registration key tool during registration key generation.
Can it be possible for anybody to do the license/registration file for my compiled Excel workbook?
No. Nobody can make license/registration file for your compiled excel files except you. The XCell Compiler is designed such way that only you can do it from your ‘DoneEx XCell Compiler’ registered computers.