I am looking for hardware TOTP system-on-chip, where it would not be possible for an adversary to extract the shared secret (TOTP seed in other words). I am researching an application, where one same seed has to be used in large number of hardware tokens for a long time.
The closest I could find is a chip for biometric passport, where there is a secret key burnt at manufacturing stage, so that it is not extractable yet used internally for signing or decryption - see "chip authentication" at https://www.readid.com/blog/cloning-detection-epassports.
Accordingly, I am looking for similar security level but different function (reliably hiding totp seed as opposed to identity). Could you please point me out to the right direction?