HistoTrust: Ethereum-Based Attestation of a Data History Built with OP-TEE and TPM.

Device- or user-centric system architectures allow everyone to manage their personal or confidential data. But how to provide the trust required between the stakeholders of a given ecosystem to work together, each preserving their interest and their business? HistoTrust introduces a solution to this problem. A system architecture separating the data belonging to each stakeholder and the cryptographic proofs (attestations) on their history is implemented. An Ethereum ledger is deployed to maintain the history of the attestations, thus guaranteeing their tamperresistance, their timestamp and their order. The ledger allows these attestations to be shared between the stakeholders in order to create trust without revealing secret or critical data. In each IoT device, the root-of-trust secrets used to attest the data produced are protected at storage in a TPM ST33 and during execution within an ARM Cortex-A7 TrustZone. The designed solution aims to be resilient, robust to software attacks and to present a high level of protection against side-channel attacks and fault injections. Furthermore, the real-time constraints of an embedded industrial application are respected. The integration of the security measures does not impact the performance in use.