Securing a Excel-file with a serial

**tomkorver** · 06-05-2009, 05:27 AM

Hi,

I have made a pretty complicated excel-file with VBA-code.
Without the VBA-code the program isn't functional.
I'm looking for a way to secure this program with a serial.

Something like; when the program starts (or as soon as macro's are enabled)
it asks for a serial (that I gave through email) and it will save it to a protected cell. Next time the program starts it will validate this serial with some formula.

However, any other suggestions are welcome how to prevent users without
valid registration to use this file.

Kind regards,
Tom Korver

**royUK** · 06-05-2009, 05:46 AM

that idea could be cracked in no time. There are various ways to do this, but they can all be avoided by someone with the right knowledge and/or tools. Excel is not a secure environment

**tomkorver** · 06-05-2009, 12:45 PM

I know it will be possible to crack this since Excel is not the right platform to make software 100% secure, but the point is simply to discourage an avarage user to copy it to someone else.
I would like to see an example of how to do this, including all vulnerabilities that come with it.
Any suggestions?