If you're running the software on hardware you "control" (like phones or IoT things) you can use "secure enclave" features to support a complex PKI for the soft

If you're running the software on hardware you "control" (like phones or IoT things) you can use "secure enclave" features to support a complex PKI for the software runNing on the Thing. But this is less about copy protection than about the need to keep rogue (i.e., bot/malware) from being installed on the box.