Methods and arrangements to control access to cryptographic keys and to attest to the approved configurations of computer platforms able to access these keys, which include trusted platform modules (TPMs) are contemplated. Embodiments include transformations, code, state machines or other logic to control access to a cryptographic key by creating an authorization blob locking authorization data to access the cryptographic key to platform configuration register (PCR) values of a TPM, the PCR values representing a configuration of a computing platform. Embodiments may also involve generating a first TPM cryptographic key bound to PCR values, receiving a second TPM cryptographic key owned by software, and receiving evidence of the identity of an upgrade service controlling the upgrading of the software. Embodiment may also include certifying the first TPM cryptographic key; certifying the second TPM cryptographic key; concatenating the first certification, the second certification, and the evidence of the identity of the upgrade service; and signing the concatenation.