It’s a real pain I tell ya! I’ve been researching the various app stores.
Autodesk has the Entitlement API, which is supercool from a developer’s perspective.
BricsCAD, well I think you need to pre upload keys, so I don’t see how to use hardware info like a MAC address.
Haven’t looked in depth at any of the other stores.
Keep it simple, I had one application that I went ballistic on, people are still using the software after 20 years, which is pretty crazy. I had a request to do an update after 15 years and I could not remember WTF I did, so yeah, I just ripped all the license stuff out.
Now I’m thinking just some encrypted key, like a song verse
TmV2ZXIgZ29ubmEgZ2l2ZSB5b3UgdXAKTmV2ZXIgZ29ubmEgbGV0IHlvdSBkb3duCk5ldmVyIGdvbm5hIHJ1biBhcm91bmQgYW5kIGRlc2VydCB5b3UKTmV2ZXIgZ29ubmEgbWFrZSB5b3UgY3J5Ck5ldmVyIGdvbm5hIHNheSBnb29kYnllCk5ldmVyIGdvbm5hIHRlbGwgYSBsaWUgYW5kIGh1cnQgeW91
Of course I'll use real encryption..
PS Bonus points if you can crack it