[sdiy] Lockout / DRM chips?

[Rainer Buchty]

On Wed, 9 Sep 2026, cheater cheater via Synth-diy wrote:

> Has anyone ever worked with such things as lockout or DRM chips?

Yes. We actually design such. But they don't work the way you like them 
to work -- it's more about putting individual, non-forgeable 
fingerprints into the chip (aka "physical uncloneable functions", PUFs) 
so that the vendor then knows which are their chips -- and, by 
exclusion, knows which ones are illegitimate overproduction hitting the 
market. The official driver / firmware will then check whether it runs 
on "true" hardware and refuse to work otherwise. Or using such 
devices as the root of trust for any subsequent secure-booting / trusted 
execution environment.

We also do the other way round, i.e., applying methods (both in HW and 
SW) to check against chips that have been meddled with during 
fabrication ("hardware trojans") or already during design time (hardware 
trojans in netlists), essentially by comparing run-time 
measurements against a known gold master or detecting suspicious 
"typical" networks of known trojan approaches.

The latter approach could theoretically be applied here, but only if 
said company would do things so against all standards that you can get a 
safe identification. After all, you don't want to accidentally shut out 
one of the others. (In your case, a false positive is way worse than a 
false negative.)

But what can they do so wrong without breaking their very own function? 
After all, such detection then can only be done on the level of 
interfacing -- but, there, line signals are line signals, modulation 
voltages are modulation voltages, MIDI is MIDI, either classic or USB.

Sure, you could then just bluntly refuse to work with any USB device 
showing a certain vendor / device ID, but that would be easily enough 
defeated.

So as much as you dislike said company, there's neither a proper 
technical way to achieve what you want, nor would I expect that any 
major player would join such an alliance.

Rainer