Techniques are described herein for security hardened processing devices. For example, a method can include performing a secure boot of a processing device of a computer system. The processing device is configured as a root of trust for a secure boot process. The computer system can include the processing device and a non-volatile memory storing a basic input/output system (BIOS) for the secure boot process. The method can include identifying a set of programmable fuses of the processing device, deriving an encryption key using a value encoded by the set of programmable fuses in the processing device, and authenticating the BIOS to perform the secure boot process using a key derivation algorithm based on the encryption key.