A Fast and Simple Partially Oblivious PRF, with Applications

Attribute-based credentials (ABCs) provide an efficient way to transfer custody of personal and private data to the final user, while minimizing the risk of sensitive data revelation and thus granting anonymity. Nevertheless, this method cannot detect whether one attribute has been used more than once without compromising anonymity when the emitter and consumer collude with one another. The protocol proposed in this article deals with this issue by using a modification of ZSS pairing-based short signatures over elliptic curves and Verheul’s self-blinded credentials scheme. Each user can generate an identifier (pseudonym) that is unique and verifiable by everyone in a given scope, without compromising anonymity. However, the identifier cannot be reused in the same scope, since such reuse would be detected.

show abstract

“…Independently, Tyagi et al [22] presented the same construction, along with a complete security proof.…”

Section: State Of the Artmentioning

confidence: 98%

Attribute Based Pseudonyms: Anonymous and Linkable Scoped Credentials

2022

View full text Add to dashboard Cite

show abstract

“…We note that in the setting where the evaluator rate-limits the number of evaluations per user, the protocol can trivially be updated to send the identity of the user (or a fixed pseudonym) together with the blinded value, and the evaluator evaluates a partially oblivious PRF where the identity is a public input to the function together with the secret evaluation key. Implementing the techniques from [53], [54] allows us to perform this slightly different evaluation without (noticeable) increased computation nor communication compared to the protocol we have described.…”

Section: Setup Party Servermentioning

confidence: 99%

BRAKE: Biometric Resilient Authenticated Key Exchange

Bauspieß,

Silde,

Poljuha

et al. 2024

IEEE Access

View full text Add to dashboard Cite

Biometric data are uniquely suited for connecting individuals to their digital identities. Deriving cryptographic key exchange from successful biometric authentication therefore gives an additional layer of trust compared to password-authenticated key exchange. However, biometric data are sensitive personal data that need to be protected on a long-term basis. Furthermore, efficient feature extraction and comparison components resulting in high intra-subject tolerance and inter-subject distinguishability, documented with good biometric performance, need to be applied in order to prevent zero-effort impersonation attacks. In this work, we present a novel protocol for Biometric Resilient Authenticated Key Exchange that fulfils the above requirements of biometric information protection compliant with the international ISO/IEC 24745 standard. In our protocol, we present a novel modification of unlinkable fuzzy vault schemes that allows their connection with oblivious pseudo-random functions to achieve resilient protection against offline attacks crucial for the protection of biometric data. Our protocol is independent of the biometric modality and can be implemented based on the security of discrete logarithms as well as lattices. We provide an open-source implementation of both instantiations of our protocol which achieve real-time efficiency with transaction times of less than one second from the image capture to the completed key exchange. INDEX TERMSAuthenticated key exchange, biometric information protection, fuzzy vault, oblivious pseudo-random function.At first sight, the performance preservation requirement in

show abstract