Reconfigurable trusted computing in hardware

Trusted Computing (TC) is an emerging technology towards building trustworthy computing platforms. The TrustedComputing Group (TCG) has proposed several specifications to implement TC functionalities by extensions to common computing platforms, particularly the underlying hardware with a Trusted Platform Module (TPM).

However, actual TPMs are mostly available for workstations and servers nowadays and rather for specific domainapplications and not primarily for embedded systems. Further, the TPM specifications are becoming monolithic andmore complex while the applications demand a scalable and flexible usage of TPM functionalities.

In this paper we propose a reconfigurable (hardware) architecture with TC functionalities where we focus on TPMsas proposed by the TCG specifically designed for embedded platforms. Our approach allows for (i) an efficient andscalable design and update of TPM functionalities, in particular for hardware-based crypto engines and accelerators, (ii) establishing a minimal trusted computing base in hardware, (iii) including the TPM as well as its functionalities into the chain of trust that enables to bind sensitive data to the underlying reconfigurable hardware, and (iv) designing a manufacturer independent TPM. We discuss possible implementations based on current FPGAs and point out the associated challenges, in particular with respect to protection of the internal TPM state since it must not be subject to manipulation, replay, and cloning