Practical and Privacy-Preserving TEE Migration
G. Arfaoui, S. Gharout, J.-F. Lalande, and J. Traore.

Trusted Execution Environments (TEE) are becoming widely deployed in new smartphone generation. Running within the TEE, the Trusted Applications (TA) belong to diverse service providers. Each TA manipulates a profile, constituted of secret credentials and user’s private data. Normally, a user should be able to transfer his TEE profiles from a TEE to another compliant TEE. However, TEE profile migration implies security and privacy issues in particular for TEE profiles that require explicit agreement of the service provider. In this paper, we first present our perception of the deployment and implementation of a TEE: we organize the TEE into security domains with different roles and privileges. Based on this new model, we build a migration protocol of TEE profiles ensuring its confidentiality and integrity. To this end, we use a reencryption key and an authorization token per couple of devices, per service provider and per transfer. The proposed protocol has been successfully validated by AVISPA, an automated security protocol validation tool.