ms-tpm-20-ref

One reasonable way to do this could involve running the reference TPM2 simulator [0] on the Arduino. It's just a C library that already implements all the cryptographic routines and TPM2 commands. In fact, this is basically how TPM vendors implement their chips. They just generally have: - A lot more hardening against physical attacks - Cryptographic libraries optimized for their low-resource hardware - (sometimes) a vendor certificate for a primary TPM key, aka an "EK cert" Certainly a TPM running on an Arduino wouldn't have the physical hardware properties of a "real" TPM. But you could probably get it into a state with similar software properties. [0] https://github.com/microsoft/ms-tpm-20-ref

It depends on how the TPM is being used by the OS and its apps. If it’s purely being used for the crypto key storage and crypto operations, then you can probably use something like the MS reference implementation [0]. If the OS requires attestation and endorsement, there is a manufacturer key pair that is embedded into the chip that you can use to attest and verify that the TPM you are interacting with is indeed from a particular manufacturer. That aspect would not be doable for an emulated DIY TPM. [0] https://github.com/microsoft/ms-tpm-20-ref