Direct anonymous attestation

Abstract

direct anonymous attestation, DAA, trusted computing, group signatures This paper describes the direct anonymous attestation scheme (DAA). This scheme was adopted by the Trusted Computing Group as the method for remote authentication of a hardware module, called trusted platform module (TPM), while preserving the privacy of the user of the platfo rm that contains the module. Direct anonymous attestation can be seen as a group signature without the feature that a signature can be opened, i.e., the anonymity is not revocable. Moreover, DAA allows for pseudonyms, i.e., for each signature a user (in agreement with the recipient of the signature) can decide whether or not the signature should be linkable to another signature. DAA furthermore allows for detection of "known" keys: if the DAA secret keys are extracted from a TPM and published, a verifier can detect that a signature was produced using these secret keys. The scheme is provably secure in the random oracle model under the strong RSA and the decisional Diffie-Hellman assumption. May 18, 2004Abstract This paper describes the direct anonymous attestation scheme (DAA). This scheme was adopted by the Trusted Computing Group as the method for remote authentication of a hardware module, called trusted platform module (TPM), while preserving the privacy of the user of the platform that contains the module. Direct anonymous attestation can be seen as a group signature without the feature that a signature can be opened, i.e., the anonymity is not revocable. Moreover, DAA allows for pseudonyms, i.e., for each signature a user (in agreement with the recipient of the signature) can decide whether or not the signature should be linkable to another signature. DAA furthermore allows for detection of "known" keys: if the DAA secret keys are extracted from a TPM and published, a verifier can detect that a signature was produced using these secret keys. The scheme is provably secure in the random oracle model under the strong RSA and the decisional Diffie-Hellman assumption.

Automatic Verification of Privacy Properties in the Applied pi Calculus

“…As case studies we demonstrate the suitability of our approach by modelling the privacy properties of the electronic voting protocol FOO [10] and Direct Anonymous Attestation (DAA) [4].…”

“…The Direct Anonymous Attestation (DAA) scheme provides a means for remotely authenticating a trusted platform whilst preserving the user's privacy [4]. In [15], two of the authors have shown that corrupt administrators are able to violate the privacy of the host.…”

“…Using our extended calculus we are now able to provide a formal and automatic proof that the rectified protocol proposed in [15] satisfies its privacy requirements. We start with a short description of the protocol (for a more complete description, see [4,15]). …”

“…Current research into applications such as electronic voting, fair exchange and trusted computing has resulted in a plethora of new requirements which protocols must satisfy (e.g. [11,4]). Some of these properties cannot easily be expressed using traditional reachability techniques but can be written as equivalences.…”

“…Using our approach we provide the first automated proof that the electronic voting protocol due to Fujioka, Okamoto & Ohta (FOO) [10] satisfies privacy. As a second case study we provide a formal methods proof that the Direct Anonymous Attestation (DAA) [4] protocol also satisfies privacy (the DAA authors provided a provable security proof). An extended version of this paper [9] and our ProVerif source code are available at http://www.cs.bham.ac.uk/˜bas/.…”