Edhy Rijo (01/15/2009)
Philipp Guntermann (01/15/2009)
just noticed you propably meant how we detect if a users claim of hardware change may be
detected by our licencing shema instead of what i answered to.Yes, that is what I meant. In my case, I have some smart customers with branch offices in which they should also pay a license for the use of the software at each branch office.
What I am trying to avoid is allowing the customer to have multiple workstations working under the same license and have a smart customer trying to use one of those workstation from another branch office and skip paying for that branch office license.
Obviously in your case, you don't really care, if they move one licensed workstation to another office and work from there, but as you explained, your method of comparing the hardware key information files will do the trick to find out if the computer has been replaced.
Thanks for the information.
yes. the trick to that is that the hw-id file is rewritten each time the application is started just before the licence validation is performed.
as said, the weak-point is the possible reverse enginering of our dll that carriers the key calculation for the encryption. we could minimize that by buying some obfuscation software tho. i had a look at a few, and the cheap ones tended to also have cheap results, while we won't afford the more expensive ones 
also i noticed that some developers of obfuscation products for .net also offer .net dissambling software, which made me wonder weather that whole topic is just a big ripp-off 