>IMO best way to implement license check is: using asymmetric crypto (so it's impossible to write keygen) and online activation (so it's impossible to share key

>IMO best way to implement license check is: using asymmetric crypto (so it's impossible to write keygen) and online activation (so it's impossible to share key). I believe from my experiences downloading CLASS and MYTH game rips from sketchy IRC channels on DALnet that even this method can be subverted by simply patching out the online activation check. The only feasible way to combat this that I'm aware of is to have some required code/data live on the company's server and thus force always-online to use the software.