Covert Identity Information in Direct Anonymous Attestation (DAA)

Direct anonymous attestation (DAA) is a practical and efficient protocol for authenticated attestation with satisfaction of strong privacy requirements. This recently developed protocol is already adopted by the Trusted Computing Group and included in the standardized trusted platform module TPM. This paper shows that the main privacy goal of DAA can be violated by the inclusion of covert identity information. This problem is very relevant, as the privacy attack is both efficient and very difficult to detect.