License Key (Or Something Like This)

[aerodoc]

I am considering selling some Excel sheets, but don't know how to prevent free redistribution on unauthorized machines.

I have looked into a few programs like LockXLS, but thought that was bit overkill and intrusive to the user.

I was thinking of something very simple. For example, the user could send you something specific to just that machine (math id perhaps?) and you could send them a file back that has code. The VBA would have an algorithm that relates the two and checks to see if it is valid.

I guess I am just looking for something very simple and unobtrusive. Any ideas?

[Blade Hunter]

I am considering selling some Excel sheets, but don't know how to prevent free redistribution on unauthorized machines.

I have looked into a few programs like LockXLS, but thought that was bit overkill and intrusive to the user.

I was thinking of something very simple. For example, the user could send you something specific to just that machine (math id perhaps?) and you could send them a file back that has code. The VBA would have an algorithm that relates the two and checks to see if it is valid.

I guess I am just looking for something very simple and unobtrusive. Any ideas?

One potential issue with that is if the user upgrades their machine. If they have paid for a sheet which they then try to use on a new machine they will not be happy, Unless you are permanantly tethered to your machine to generate them a new one they will not be impressed.

I suppose you could come up with some sort of system where they are given a challenge key, they then enter that and their password in to a site (which you would have to create) the site would then email the response to the user registered for that sheet.

Make it happen once a month so not so intrusive that it is a pain but once it is locked for the month, it is permanantly locked until they get the response correct.

Just thinking out loud here but that would probably work.

[aerodoc]

Yeah, I understand. It's not an easy solution, but other programs use this approach. I know there are other software solutions to help out (i.e. LockXLS) but they all seems overly intrusive.

[macropod]

Hi aerodoc,

There really isn't anything you can do to protect an ordinary Excel file from 'unlicensed use'. Whatever form of protection you implement can most likely be broken very quickly. Hence software like LockXLS.

[aerodoc]

What are the other options besides LockXLS? Money is not really an issue, I am looking for the best solution available.

[Bob Phillips]

I looked at AppSentinel a few years back and it seemed good. I think you would need to implement a VB DLL alongside with some key code and the AppSentinel checks, I couldn't figure how you could add it to VBA and keep it secure..

[Ctrl]

I can also suggest DoneEx XCell Compiler.

http://doneex.com/