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You can authenticate to a TPM via HMAC and a shared secret key, so also the two other points can be addressed with code. The catch is that the other elements n
by zimmerfrei 5y ago
You can authenticate to a TPM via HMAC and a shared secret key, so also the two other points can be addressed with code.
The catch is that the other elements need to be able to store the secret, and they need to "pair" to the TPM when the motherboard is assembled. Also, scenarios concerning the legitimate replacement of the CPU need to be addressed. Those are all key management tasks that manufacturers are not good at in general... so here we are with unauthenticated sessions...
- cryptonector 5y ago> You can authenticate to a TPM via HMAC and a shared secret key, ... > The catch is that the other elements need to be able to store the secret... Yes, that catch is the problem. You can also authenticate the TPM to the host w/o authenticating the host to the TPM -- all you need is to be able to record the public key of a suitable primary (say, the EK) on the TPM that has fixedTPM and fixedParent set. Less messy than having to store a secret on the host, but not really enough to solve the reset issue.