Direct Anonymous Attestation Scheme Research Articles

Integrating Privacy into the Electric Vehicle Charging Architecture

The Electric Vehicle (EV) charging architecture consists of several actors which communicate with different protocols. A serious issue is the lack of adequate privacy-preserving measures that enables the generation of movement profiles or inferring consumer habits by all of the involved actors. In this paper, we propose an extension of a Trusted Platform Module (TPM)-based Direct Anonymous Attestation (DAA) scheme to enable privacy-preserving charging authorization and billing. Our implementation shows that our solution can be easily integrated into existing protocols of the Plug-and-Charge (PnC) EV charging architecture and introduces only minor overhead. The formal analysis using the Tamarin prover shows the security and privacy of our protocol extension.

Anonymity and rewards in peer rating systems1

When peers rate each other, they may rate inaccurately to boost their own reputation or unfairly lower another’s. This could be mitigated by having a reputation server incentivise accurate ratings with a reward. However, assigning rewards becomes challenging when ratings are anonymous, since the reputation server cannot tell which peers to reward for rating accurately. To address this, we propose an anonymous peer rating system in which users can be rewarded for accurate ratings, and we formally define its model and security requirements. In our system ratings are rewarded in batches, so that users claiming their rewards only reveal they authored one in this batch of ratings. To ensure the anonymity set of rewarded users is not reduced, we also split the reputation server into two entities, the Rewarder, who knows which ratings are rewarded, and the Reputation Holder, who knows which users were rewarded. We give a provably secure construction satisfying all the security properties required. For our construction we use a modification of a Direct Anonymous Attestation scheme to ensure that peers can prove their own reputation when rating others, and that multiple feedback on the same subject can be detected. We then use Linkable Ring Signatures to enable peers to be rewarded for their accurate ratings, while still ensuring that ratings are anonymous. Our work results in a system which allows accurate ratings to be rewarded, whilst still providing anonymity of ratings with respect to the central entities managing the system.

V-LDAA: A New Lattice-Based Direct Anonymous Attestation Scheme for VANETs System

Privacy protection and message authentication issues in VANETs have received great attention in academia. Many authentication schemes in VANETs have been proposed, but most of them are based on classical difficult problems such as factorization in RSA setting or Elliptic Curve setting and are therefore not quantum resistant. If a quantum computer becomes available in the next few decades, the security of these schemes will be at stake. This paper presents a vehicular lattice-based direct anonymous attestation (V-LDAA) scheme adopting an optimized signature scheme based on automorphism stability which achieves postquantum security. A distributed pseudonym update and vehicle revocation mechanism based on the lattice is introduced in this paper, which means vehicles can update their pseudonyms and revoke the identity certificate by themselves without the need for pseudonym resolutions or CRLs checking. Compared with the existing lattice-based attestation schemes in VANETs, computation costs during signing and verification operations in V-LDAA are no longer related to the number of users, which makes it suitable for large-scale VANETs. Security analysis shows that V-LDAA resists TPM theft attacks and provides users with user-controlled anonymity, user-controlled unlinkability, and unforgeability against quantum adversaries. Experimental results show that V-LDAA reduces the blind signature size by 18%. The speed of blind signing is increased by 30%, and blind verification operation is accelerated 3 times compared with the existing lattice-based direct anonymous attestation (LDAA) scheme.

Direct Anonymous Attestation With Optimal TPM Signing Efficiency

Direct Anonymous Attestation (DAA) is an anonymous signature scheme, which allows the Trusted Platform Module (TPM), a small chip embedded in a host computer, to attest to the state of the host system, while preserving the privacy of the user. DAA provides two signature modes: fully anonymous signatures and pseudonymous signatures. One main goal of designing DAA schemes is to reduce the TPM signing workload as much as possible, as the TPM has only limited resources. In an optimal DAA scheme, the signing workload on the TPM will be no more than that required for a normal signature like ECSchnorr. To date, no scheme has achieved the optimal signing efficiency for both signature modes. In this paper, we propose the first DAA scheme which achieves the optimal TPM signing efficiency for both signature modes. In this scheme, the TPM takes only a single exponentiation to generate a signature, and this single exponentiation can be pre-computed. Our scheme can be implemented using the existing TPM 2.0 commands, and thus is compatible with the TPM 2.0 specification. We benchmarked the TPM 2.0 commands needed for three DAA use cases on an Infineon TPM 2.0 chip, and also implemented the host signing and verification algorithm for our DAA scheme on a laptop with 1.80GHz Intel Core i7-8550U CPU. Our experimental results show that our DAA scheme obtains a total signing time of about 144 ms for either signature mode, while with pre-computation we can obtain a signing time of about 65 ms. Based on our benchmark results for the pseudonymous signature mode, our scheme is roughly <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\times $ </tex-math></inline-formula> (resp., <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$5\times $ </tex-math></inline-formula> ) faster than the existing DAA schemes supported by TPM 2.0 in terms of total (resp., online) signing efficiency.

A lightweight attribute-based authentication system with DAA

In cloud computing environment, while preventing users from illegally accessing resources, various cloud service systems must provide protection for authorized users of their personal sensitive information. Attribute-based authentication (ABA) makes it possible to solve the above problems. An efficient ABA system was put forward by extending the direct anonymous attestation (DAA) scheme of Brickell et al. During the construction of the new system, the technique of lightweight ciphertext policy attribute-based encryption was adopted, and the online computing task of users was optimized. Compared with other similar systems, the new system is characterized by the use of trusted computing technology to improve the level of privacy protection of users, and the computational complexity of users in the authentication stage is independent of the size of access policy.

More efficient, provably-secure direct anonymous attestation from lattices

Abstract The Cloud-Edges (CE) framework, wherein small groups of Internet of Things (IoT) devices are serviced by local edge devices, enables a more scalable solution to IoT networks. The trustworthiness of the network may be ensured with Trusted Platform Modules (TPMs). This small hardware chip is capable of measuring and reporting a representation of the state of an IoT device. When connecting to a network, the IoT platform might have its state signed by the TPM in an anonymous way to prove both its genuineness and secure state through the Direct Anonymous Attestation (DAA) protocol. Currently standardised DAA schemes have their security supported on the factoring and discrete logarithm problems. Should a quantum-computer become available in the next few decades, these schemes will be broken. There is therefore a need to start developing a post-quantum DAA protocol. This paper presents a Lattice-based DAA (LDAA) scheme to meet this requirement. The security of this scheme is proved in the Universally Composable (UC) security model under the hardness assumptions of the Ring Inhomogeneous Short Integer Solution (Ring-ISIS) and Ring Learning With Errors (Ring-LWE) problems. Compared to the only other DAA scheme with conjectured post-quantum security available in related art, the storage requirements of the TPM are reduced twofold and the signature sizes 5 times. Moreover, experimental results show that the signing and verification operations are accelerated 1.1 and 2.0 times, respectively.

Research on direct anonymous attestation mechanism in enterprise information management

ABSTRACT Privacy leakage is becoming more and more serious in enterprise information management. To solve the poor security problems, by introducing short signatures into enterprise information managements, this paper proposes a novel direct anonymous attestation scheme. The novel scheme is based on a novel short signature scheme, which is applied into the member joining and signature phases. It simplifies the signing and verification process of member certificates and reduces its computing costs. Under the security hypothesis of Decision Diffie–Hellman and q-Strong Diffie-Hellman difficult problems, the novel attestation scheme meets the provable security of the trusted platform module specifications.

An enhanced direct anonymous attestation scheme with mutual authentication for network-connected UAV communication systems

In network-connected UAV (NC-UAV) communication systems, user authentication is replaced by platform identity authentication and integrity check because many NC-UAVs are operated without human intervention. Direct anonymous attestation (DAA) is an attractive cryptographic scheme that provides an elegant balance between platform authentication and anonymity. However, because of the low-level computing capability and limited transmission bandwidth in UAV, the existing DAA schemes are not suitable for NC-UAV communication systems. In this paper, we propose an enhanced DAA scheme with mutual authentication (MA-DAA scheme), which meets the security requirements of NC-UAV communication systems. The proposed MA-DAA scheme, which is based on asymmetric pairings, bundles the identities of trusted platform module (TPM) and Host to solve the malicious module changing attacks. Credential randomization, batch proof and verification, and mutual authentication are realized in the MA-DAA scheme. The computational workload in TPM and Host is reduced in order to meet the low computation and resource requirements in TPM and Host. The entire scheme and protocols are presented, and the security and efficiency of the proposed MA-DAA scheme are proved and analyzed. Our experiment results also confirm the high efficiency of the proposed scheme.

Enhanced security model and efficient construction for direct anonymous attestation

Direct anonymous attestation (DAA) is a cryptographic scheme which enables the remote authentication of a trusted platform whilst preserving privacy under the user's control. In this paper, we first present the enhanced security model for DAA, in which more precise security notions demanded from DAA are defined than that in any previous model. Then we propose a novel approach for constructing an efficient DAA scheme: we design a secure two-party computation protocol for the join/issue protocol of DAA, and construct the DAA scheme concretely under the q-SDH assumption, DL assumption and XDH assumption. Based on the enhanced security model, we prove that our DAA scheme meets user-controlled anonymity, user-controlled traceability and non-frameability in the random oracle model. Finally, compared with other existing DAA schemes, our DAA scheme has better performance.

Enhanced security model and efficient construction for direct anonymous attestation

Direct anonymous attestation (DAA) is a cryptographic scheme which enables the remote authentication of a trusted platform whilst preserving privacy under the user's control. In this paper, we first present the enhanced security model for DAA, in which more precise security notions demanded from DAA are defined than that in any previous model. Then we propose a novel approach for constructing an efficient DAA scheme: we design a secure two-party computation protocol for the join/issue protocol of DAA, and construct the DAA scheme concretely under the q-SDH assumption, DL assumption and XDH assumption. Based on the enhanced security model, we prove that our DAA scheme meets user-controlled anonymity, user-controlled traceability and non-frameability in the random oracle model. Finally, compared with other existing DAA schemes, our DAA scheme has better performance.

Larp-Protocol for Secure Location Services based on Direct Anonymous Attestation (DAA) Scheme in Manet

Larp-Protocol for Secure Location Services based on Direct Anonymous Attestation (DAA) Scheme in Manet

Formal analysis of privacy in Direct Anonymous Attestation schemes

This article introduces a definition of privacy for Direct Anonymous Attestation schemes. The definition is expressed as an equivalence property which is suited to automated reasoning using Blanchet's ProVerif. The practicality of the definition is demonstrated by analysing the RSA-based Direct Anonymous Attestation protocol by Brickell, Camenisch & Chen. The analysis discovers a vulnerability in the RSA-based scheme which can be exploited by a passive adversary and, under weaker assumptions, corrupt issuers and verifiers. A security fix is identified and the revised protocol is shown to satisfy our definition of privacy.

A delegation based cross trusted domain direct anonymous attestation scheme

Direct Anonymous Attestation (DAA) is a complex cryptographic protocol for remote attestation and provides both signer authentication and privacy. It was adopted by the Trusted Computing Group (TCG) as a technical standard. However, the DAA scheme in TCG specifications is designed for the single trusted domain attestation, and cannot be deployed in different trusted domain directly. It limits its application range in mobile networks, cloud computing, Internet of Things networks when users and authentication servers belong to different domains. Based on delegation of the trusted relationship, a new cross trusted domain direct anonymous attestation scheme is proposed in this paper. The proxy signature is used for trusted relationship delegation among different domains, and the DAA method is used for the computation platform authentication when a trusted platform accessing different trusted domains. Then the authentication protocol is designed and analyzed under Canetti–Krawczyk (CK) model for the platform remote attestation. The further analysis shows that our proposal can resist platform masquerade attacks and replay attacks, and the authentication protocol is provably secure. The security of the DAA remote attestation system is enhanced by the session key agreement. Finally, a prototype implementation and some experiments are given, the results show that the proposed scheme is effective and suitable for cross domain applications.

基于身份的跨域直接匿名认证机制

In view of the shortcomings of high computational overhead and failure in cross-domain anonymous authentication existed in TCG DAA program, this paper proposes a cross-domain direct anonymous attestation scheme based on identity, in which the proxy signature and direct anonymous attestation technology are employed for the trusted mobile platform (TMP) in mobile Internet. On the base of the legitimacy of the DAA signature, the verifier of remote domain identifies the authenticity of TMP, during which the remote attestation system is security-enhanced by a key agreement. Analyzed in Canetti-Krawczyk (CK) model, this authentication scheme is anonymous, unrelated and high-performance. We demonstrate that it can resist masquerade attacks, reply attacks and platform substitution attacks. It is effective and more suitable for the mobile Internet and other wireless networks.

The theory and practice in the evolution of trusted computing

Trusted computing (TC) is an emerging technology to enhance the security of various computing platforms by a dedicated secure chip (TPM/TCM), which is widely accepted by both the industrial and academic world. This paper attempts to sketch the evolution of TC from the view of our theoretical and engineering work. In theory, we focus on protocol design and security analysis. We have proposed the first ECDAA protocol scheme based on q-SDH assumption, which highlights a new way to design direct anonymous attestation scheme. In technical evolution, we discuss the key technologies of trust chain, trusted network connection and TC testing and evaluation. We break through several key technologies such as trusted boot, OS measurement and remote attestation, and implement a TC system from TPM/TCM to network. We also design and implement a testing and evaluation system of TC platform, which is the first one put into practical application in China. Finally, with the rapid development of cloud computing and mobile applications, TC is moving toward some new directions, such as the trust in cloud and mobile environments, new TPM standard, and flexible trust execution environment trust establishment method.

Anonymous attestation with user-controlled linkability

This paper is motivated by the observation that existing security models for direct anonymous attestation (DAA) have problems to the extent that insecure protocols may be deemed secure when analysed under these models. This is particularly disturbing as DAA is one of the few complex cryptographic protocols resulting from recent theoretical advances actually deployed in real life. Moreover, standardization bodies are currently looking into designing the next generation of such protocols. Our first contribution is to identify issues in existing models for DAA and explain how these errors allow for proving security of insecure protocols. These issues are exhibited in all deployed and proposed DAA protocols (although they can often be easily fixed). Our second contribution is a new security model for a class of “pre-DAA scheme”, that is, DAA schemes where the computation on the user side takes place entirely on the trusted platform. Our model captures more accurately than any previous model the security properties demanded from DAA by the trusted computing group (TCG), the group that maintains the DAA standard. Extending the model from pre-DAA to full DAA is only a matter of refining the trust models on the parties involved. Finally, we present a generic construction of a DAA protocol from new building blocks tailored for anonymous attestation. Some of them are new variations on established ideas and may be of independent interest. We give instantiations for these building blocks that yield a DAA scheme more efficient than the one currently deployed, and as efficient as the one about to be standardized by the TCG which has no valid security proof.

Direct Anonymous Attestation Scheme in Cross Trusted Domain for Wireless Mobile Networks

Direct Anonymous Attestation Scheme in Cross Trusted Domain for Wireless Mobile Networks

Enhanced Privacy ID: A Direct Anonymous Attestation Scheme with Enhanced Revocation Capabilities

Direct Anonymous Attestation (DAA) is a scheme that enables the remote authentication of a Trusted Platform Module (TPM) while preserving the user's privacy. A TPM can prove to a remote party that it is a valid TPM without revealing its identity and without linkability. In the DAA scheme, a TPM can be revoked only if the DAA private key in the hardware has been extracted and published widely so that verifiers obtain the corrupted private key. If the unlinkability requirement is relaxed, a TPM suspected of being compromised can be revoked even if the private key is not known. However, with the full unlinkability requirement intact, if a TPM has been compromised but its private key has not been distributed to verifiers, the TPM cannot be revoked. Furthermore, a TPM cannot be revoked from the issuer, if the TPM is found to be compromised after the DAA issuing has occurred. In this paper, we present a new DAA scheme called Enhanced Privacy ID (EPID) scheme that addresses the above limitations. While still providing unlinkability, our scheme provides a method to revoke a TPM even if the TPM private key is unknown. This expanded revocation property makes the scheme useful for other applications such as for driver's license. Our EPID scheme is efficient and provably secure in the same security model as DAA, i.e., in the random oracle model under the strong RSA assumption and the decisional Diffie-Hellman assumption.

A New Method of Performance Estimate of Direct Anonymous Attestation Scheme in TCG

A New Method of Performance Estimate of Direct Anonymous Attestation Scheme in TCG

A new process and framework for direct anonymous attestation based on symmetric bilinear maps

For the problem of the original direct anonymous attestation (DAA) scheme’s complexity and great time consumption, a new DAA scheme based on symmetric bilinear pairings is presented, which gives a practical solution to ECC-based TPM in protecting the privacy of the TPM. The scheme still includes five procedures or algorithms: Setup, Join, Sign, Verify and Rogue tagging, but gets rid of zero-knowledge proof and takes on a new process and framework, of which the main operations are addition, scalar multiplication and bilinear maps on supersingular elliptic curve systems. Moreover, the scheme adequately utilizes the properties of bilinear maps as well as the signature and verification of the ecliptic curve system itself. Compared with other schemes, the new DAA scheme not only satisfies the same properties, and shows better simplicity and high efficiency. This paper gives not only a detailed security proof of the proposed scheme, but also a careful performance analysis by comparing with the existing DAA schemes.