Multiple trusted platform modules within a data processing system are used in a redundant manner that provides a reliable mechanism for securely storing secret data at rest that is used to bootstrap a system trusted platform module. A hypervisor requests each trusted platform module to encrypt a copy of the secret data, thereby generating multiple versions of encrypted secret data values, which are then stored within a non-volatile memory within the trusted platform. At some later point in time, the encrypted secret data values are retrieved, decrypted by the trusted platform module that performed the previous encryption, and then compared to each other. If any of the decrypted values do not match a quorum of values from the comparison operation, then a corresponding trusted platform module for a non-matching decrypted value is designated as defective because it has not been able to correctly decrypt a value that it previously encrypted.