Excel VBA Addin Licensing Tools

[ttt123]

Hello, I have an Excel Addin that I would like to distribute to clients, but I would like to protect the code and have licensing constraints like the number of computers it can be used on and the time duration it can be used.

I know that Excel's code protection is supposed to be pretty weak and that it can be easily hacked (is this still the case in Excel 2010)?

Are there any guides or can anyone offer any useful tips for creating licenses that can be used for a limited duration and only on a certain number of computers? Or if there are any good 3rd party apps that will do this.

I was thinking of writing my own vba code that could check against the system time for time constraints, license based on the drive serial number: DriveSerialNumber = CreateObject("Scripting.FileSystemObject").GetDrive("C:\").SerialNumber but if the VBA source code can be cracked, you don't really get much security on your licensing since someone could just view your licensing code and change it.

any suggestions would be greatly appreciate.
Thanks,
Taylour

 

[dk]

Hi mate

It's been discussed quite a few times before e.g. http://www.mrexcel.com/forum/showthread.php?t=67918&

VBA project protection is weak as you mentioned and Excel 2010 is no different. If you want proper security i.e. no source code distributed with your application then you might want to consider a COM-addin (which you can create using Visual Basic 6 or VB.NET) as these get compiled into executable files. Unfortunately you would need to modify your existing add-in code to do this (significantly if you use VB.NET, less so if you use the older VB6).


HTH
DK

 

[LogicNP]

CryptoLicensing for ActiveX is a ready to use licensing system you can use - it supports VBA as well as COM add-ins. If you are developing your Excel add-in in .Net, there is also a .Net edition of CryptoLicensing available.