Infralution Support

[lelandv]

Hi,

Having read through the FAQs on the subject, and also read your reasoning for not using host-restrictive licensing, on the basis that most implementations of this are so-called "software activation"... and of course I respect and fully support your conclusions on this issue, perhaps you might consider an alternative possibility to provide a solution for those who require host-based licensing and anti-copy protection.

What started me off on this was a simple test in that that I was able to take an application from one machine and copy it to any number of other machines if I also copied the licence key file. This rather defeats the object of protecting intellectual property from unauthorised duplication.

There is a way that anti-copy/host-based licensing could be implemented without requiring a user/provider exchange of activation parameters.

Essentially, generate the licence key as usual, but instead of using the generated key in its native form, use an algorithm to hash it against a fixed host-based signature, for example MAC address, the hardware ID of any fixed drive, or a signature element from the machine's BIOS, all of which are fairly trivial to obtain programmatically, and THAT is the key which is stored in the MyApplication.lic file.

Upon licence verification, you can perform some form of "extraction" of both the generic licence key provided at the time of software purchase/registration as well as the other fixed-host ID. From there, you can detect whether firstly the licence is valid, but also whether it is running on the machine that it was licensed for.. if all is well, you can run the application unhindered.. if the generic licence is valid but the host-key is invalid, then you know that the application and licence key have been copied to another machine, and you can take appropriate measures within the application. If the generic key is invalid or missing, well.. you already have the way to deal with that anyway.

This would provide a host-based verification of the licence and copy protection, whilst at the same time avoiding the need for any software activation process.

Just a thought.

L.

[Infralution]

If you don't use a "user/provider exchange of activation parameters" then the license key that you issue can be used on any PC. This means that the person who receives and installs the license can simply repeat the process.

If you wish to prevent copying of the license key (and program) from a PC by others who did not have access to the issued license key then this is relatively simply to do currently. The simplest solution is to change the location of the license file (when you call GetLicense) to another directory - say the common application settings directory. This will prevent simple naive copying of the application. Alternatively you could load/save the license key yourself and then use the ValidateLicenseKey method to check the license key. This allows you to save the license key to registry or even encrypt it if you wish. See the CustomLicensedApplication sample for an example of this.

Since in most cases someone with access to the PC will also also have access to the original license key (since they installed it) it is probably not worth creating too involved a scheme.
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Infralution Support

[lelandv]

Yup.. sorry.. you are quite right.

A bit of a flaw in my own logic

We return you to your regularly scheduled programming

Leland