Area, Energy, and Time Assessment for a Distributed TPM for Distributed Trust in IoT Clusters

IoT clusters arise from natural human societal clusters such as a house, an airport, and a highway. IoT clusters are heterogeneous with a need for device to device as well as device to user trust. The IoT devices are likely to be thin computing clients. Due to low cost, an individual IoT device is not built to be fault tolerant through redundancy. Hence the trust protocols cannot take the liveness of a device for granted. In fact, the differentiation between a failing device and a malicious device is difficult from the trust protocol perspective. We present a minimal distributed trust layer based on distributed consensus like operations. These distributed primitives are cast in the context of the APIs supported by a trusted platform module (TPM). TPM with its 1024 bit RSA is a significant burden on a thin IoT design. We use RNS based slicing of a TPM where in each slice resides within a single IoT device. The overall TPM functionality is distributed among several IoT devices within a cluster. The VLSI area, energy, and time savings of such a distributed TMP implementation is assessed. A sliced/distributed TPM is better suited for an IoT environment based on its resource needs. We demonstrate over 90% time reduction, over 3% area reduction, and over 90% energy reduction per IoT node in order to support TPM protocols.