I think most (all?) Steam games link steam_api.dll (or something like that) which somehow figures out the running Steam process and thus the Steam ID, and then does a HTTP API request to check that you own the title.
Like 15 years ago Steam launched CEG (Custom Executable Generation) - I remember reading a write-up a while ago, but each user had a customer launcher generated on install I think, and I think there was an extra segment put into the .exe file and that was put to use somehow, though I don't know if CEG is still a thing.
The ownership check you are referring to is a local check. There is another check (involving EncryptedAppTickets) which is not local, but far fewer games use that.
CEG is long dead/was broken immediately in a pragmatic, automatable way.
Well how does Steam do DRM?
I think most (all?) Steam games link steam_api.dll (or something like that) which somehow figures out the running Steam process and thus the Steam ID, and then does a HTTP API request to check that you own the title.
Like 15 years ago Steam launched CEG (Custom Executable Generation) - I remember reading a write-up a while ago, but each user had a customer launcher generated on install I think, and I think there was an extra segment put into the .exe file and that was put to use somehow, though I don't know if CEG is still a thing.
The ownership check you are referring to is a local check. There is another check (involving EncryptedAppTickets) which is not local, but far fewer games use that.
CEG is long dead/was broken immediately in a pragmatic, automatable way.
Its easier on a system that doesn't need to do broadcast distribution and with servers available.
The same problem exists with PC games released on DVDs.
there isn't a market for gamers buying games on DVDs these days. BlueRay the same.
Of course there are voice that do want real disks but sadly that time is over. Digital sales won.
There is, at least for collector's editions. I'll continue to support physical for as long as possible.