Historically shared DRM keys are typically symmetric encryption keys, not asymmetric ones, and thus not primes. I am not aware of any instances of an "illegal p

Historically shared DRM keys are typically symmetric encryption keys, not asymmetric ones, and thus not primes. I am not aware of any instances of an "illegal prime" that was prime because it was the private part of an RSA-based DRM cryptosystem. As far as I know, all of them were either encoded as primes deliberately, or just coincidentally prime. Edit: except for this one, I guess. This one wasn't about DRM, but rather just a locked down device. TI sent bogus DMCA notices for that one, but as far as I can tell there is no solid legal theory under which those primes were illegal, and nobody ever got sued, so we can file this one under "manufacturer upset they no longer control their users' devices throws a legally meaningless fit". https://en.m.wikipedia.org/wiki/Texas_Instruments_signing_key_controversy https://en.m.wikipedia.org/wiki/Texas_Instruments_signing_ke...