Propagating trusted execution through mutual attestation

Attestation is used in a trusted computing context to verify the expected good behaviour. It defines a prover and verifier relationship. It requires the presence of an authority if any two devices want to question each other for a sensitive collaborative work. In contrast, the mutual attestation defined in this paper allows the same rank and type devices to directly evaluate each other, and manage their own cooperation. In addition, it provides the attestations with response actions so that a device with an untrusted state can be recovered with the help of others on the network. These features are supported with a Root-of-Trust (RoT) module capable of enforcing actions even on exploited devices. A proof-of-concept FPGA implementation of the proposed RoT module is demonstrated on Zynq SoCs, as an add-on extension to a RISC-V processor for establishing trust between applications of connected devices. Besides, it assists to explore the implementation decisions, abnormal execution situations, resource utilisation, and performance overheads.