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@cesarb @tthbaltazar @mjg59 Don’t confuse on-package TPMs and fTPMs. A lot of fTPMs (which run on the main core in a privileged mode) are often vulnerable to side channels. Several of the recent transient execution attacks could leak fTPM secrets. I think most of these were patched by doing some aggressive state flushing on TPM events, but people keep finding new side channels. On-package TPMs, where the TPM is a separate component either in the same package or on the same die are typically not vulnerable to these attacks. On the MS Surface laptops, there’s a Pluton subsystem on die, which runs the TPM stack. Pluton is one of the few Microsoft security products I have a lot of faith in (I worked with that team, they’re great): it stood up to over a decade of attacks from people with physical access and a strong financial incentive to break it.