[culpable_pickle]

Wouldn’t the TPM fit those requirements, presuming it could be sped up enough for the required workload

[fomine3]

Currently TPM is connected via very narrow bus.

[loup-vaillant]

Yeah, it's good enough for decrypting message headers then handing the rest of the decryption to the much more powerful main CPU. But having it handle the whole encryption? You're going to wait a while.