tpm

Will TPM2 CreatePrimary function with same parameters produce different keys on different PCs?


If I will create keys with function CreatePrimary and same function parameters on physically different PCs. Will it lead to creation of different keys?

Documentation says that CreatePrimary with same parameters will lead to creating of same object every time. But as I understand it will be true in case we are talking about same TPM. enter image description here What about different PCs (TPMs)?

If it's true (on different PCs it will lead to creation of different keys) where I can find approval of this information?


Solution

  • The primary seed is a randomly generated value that must be "at least twice the number of bits as the security strength of any symmetric or asymmetric algorithm implemented on the TPM" but is typically at least 512 bits in size. While uniqueness can not be guaranteed, such a size makes it statistically unique -- much more so than a GUID, for example.

    The primary key being derived from the seed, it will be statistically unique as well.