As the PSP arch spec said, it seems each NIC has two master key.
> each NIC has two 256-bit AES keys, called master keys, not shared with any hosts
including its own, or with any other NICs. The master keys are "critical security parameters",which are kept ephemerally in on-NIC RAM, and must not be stored on any persistent medium.
> each NIC has two 256-bit AES keys, called master keys, not shared with any hosts including its own, or with any other NICs. The master keys are "critical security parameters",which are kept ephemerally in on-NIC RAM, and must not be stored on any persistent medium.