I don't have any evidence that hardware compatibility plays any significant role at all in the persistence of insecurely-sized or badly-generated keys for public-key cryptography.
Well, sort of. But I probably could explained myself better, and maybe compatibility is not the right word, because this can be considered to go beyond compatibility.
Some remarks that I found interesting on the topic:
-While compatibility/reliability are 110% nice (compatibility being defined as "it works"), that doesn't mean full stability in generating entropy. "Components may be perfect; composition(they all together) can still be flawed", where the components are: Device Hardware, Device OS, and Device Software (KeyGen)"
- "in low-margin devices there aren't high-quality entropy sources to rely on", so its harder to know for sure that key was well generated.
- a large scale on RSA keys enabled the detection of entropy failures that manifested in the RSA keys of millions of devices. Most affected product families were lower-margin devices past their end-of-support date.
Ah. You're referring to the issue of devices which don't have sufficient sources of entropy to generate high-quality random numbers, particularly at early boot, particularly on first boot, and particularly for headless network-connected devices (like home router/gateway boxes).
Over the next few years there was quite a lot of work, including in the Linux kernel, on improving the entropy sources available to such devices, and making them more foolproof to use. https://lwn.net/Articles/724643/
The issues identified in this survey are related, but distinct. The Debian weak keys generated in 2006-8 are due to a straight up bug in Debian, and RSA keys that are of a too-small size are orthogonal. I found far fewer "inexplicable duplicate" TLS keys than Heninger
et al did in 2012.
> hardware compatibility
I don't have any evidence that hardware compatibility plays any significant role at all in the persistence of insecurely-sized or badly-generated keys for public-key cryptography.
Do you have a reason to think otherwise?