All Outputs (10)

Short structure-preserving signatures (2016)
Journal Article
Ghadafi, E. (2016). Short structure-preserving signatures. Lecture Notes in Artificial Intelligence, 9610, 305-321. https://doi.org/10.1007/978-3-319-29485-8_18

© Springer International Publishing Switzerland 2016. We construct a new structure-preserving signature scheme in the efficient Type-III asymmetric bilinear group setting with signatures shorter than all existing schemes. Our signatures consist of 3... Read More about Short structure-preserving signatures.

Stronger security notions for decentralized traceable attribute-based signatures and more efficient constructions (2015)
Journal Article
Ghadafi, E. (2015). Stronger security notions for decentralized traceable attribute-based signatures and more efficient constructions. Lecture Notes in Artificial Intelligence, 9048, 391-409. https://doi.org/10.1007/978-3-319-16715-2_21

© Springer International Publishing Switzerland 2015. We revisit the notion of Decentralized Traceable Attribute- Based Signatures (DTABS) introduced by El Kaafarani et al. (CT-RSA 2014) and improve the state-of-the-art in three dimensions: Firstly,... Read More about Stronger security notions for decentralized traceable attribute-based signatures and more efficient constructions.

Efficient Distributed tag-based encryption and its application to group signatures with efficient distributed traceability (2015)
Journal Article
Ghadafi, E. (2015). Efficient Distributed tag-based encryption and its application to group signatures with efficient distributed traceability. Lecture Notes in Artificial Intelligence, 8895, 327-347. https://doi.org/10.1007/978-3-319-16295-9_18

© Springer International Publishing Switzerland 2015. In this work, we first formalize the notion of dynamic group signatures with distributed traceability, where the capability to trace signatures is distributed among n managers without requiring an... Read More about Efficient Distributed tag-based encryption and its application to group signatures with efficient distributed traceability.

Attribute-based signatures with user-controlled linkability (2014)
Journal Article
El Kaafarani, A., Chen, L., Ghadafi, E., & Davenport, J. (2014). Attribute-based signatures with user-controlled linkability. Lecture Notes in Artificial Intelligence, LNCS, volume 8813, 256-269. https://doi.org/10.1007/978-3-319-12280-9_17

In this paper, we introduce Attribute-Based Signatures with User-Controlled Linkability (ABS-UCL). Attribute-based signatures allow a signer who has enough credentials/attributes to anonymously sign a message w.r.t. some public policy revealing neith... Read More about Attribute-based signatures with user-controlled linkability.

Decentralized traceable attribute-based signatures (2014)
Journal Article
El Kaafarani, A., Ghadafi, E., & Khader, D. (2014). Decentralized traceable attribute-based signatures. Lecture Notes in Artificial Intelligence, 8366 LNCS, 327-348. https://doi.org/10.1007/978-3-319-04852-9_17

We provide a formal security model for traceable attribute-based signatures. Our focus is on the more practical case where attribute management is distributed among different authorities rather than relying on a single central authority. By specializ... Read More about Decentralized traceable attribute-based signatures.

Formalizing group blind signatures and practical constructions without random oracles (2013)
Journal Article
Ghadafi, E. (2013). Formalizing group blind signatures and practical constructions without random oracles. Lecture Notes in Artificial Intelligence, 7959 LNCS, 330-346. https://doi.org/10.1007/978-3-642-39059-3_23

Group blind signatures combine anonymity properties of both group signatures and blind signatures and offer privacy for both the message to be signed and the signer. The primitive has been introduced with only informal definitions for its required se... Read More about Formalizing group blind signatures and practical constructions without random oracles.

Efficient signatures of knowledge and DAA in the standard model (2013)
Journal Article
Bernhard, D., Fuchsbauer, G., & Ghadafi, E. (2013). Efficient signatures of knowledge and DAA in the standard model. Lecture Notes in Artificial Intelligence, 7954 LNCS, 518-533. https://doi.org/10.1007/978-3-642-38980-1_33

Direct Anonymous Attestation (DAA) is one of the most complex cryptographic protocols deployed in practice. It allows an embedded secure processor known as a Trusted Platform Module (TPM) to attest to the configuration of its host computer without vi... Read More about Efficient signatures of knowledge and DAA in the standard model.

Efficient two-move blind signatures in the common reference string model (2012)
Journal Article
Ghadafi, E., & Smart, N. P. (2012). Efficient two-move blind signatures in the common reference string model. Lecture Notes in Artificial Intelligence, 7483 LNCS, 274-289. https://doi.org/10.1007/978-3-642-33383-5_17

Blind signatures provide a mechanism for achieving privacy and anonymity whereby a user gets the signer to sign a message of his choice without the signer learning the message, or being able to link a signature to the protocol run via which it was ob... Read More about Efficient two-move blind signatures in the common reference string model.

Groth-Sahai proofs revisited (2010)
Journal Article
Smart, N. P., Ghadafi, E., & Warinschi, B. (2010). Groth-Sahai proofs revisited. Lecture Notes in Artificial Intelligence, 6056 LNCS, 177-192. https://doi.org/10.1007/978-3-642-13013-7_11

Since their introduction in 2008, the non-interactive zero-knowledge (NIZK) and non-interactive witness indistinguishable (NIWI) proofs designed by Groth and Sahai have been used in numerous applications. In this paper, we offer two contributions to... Read More about Groth-Sahai proofs revisited.

Practical zero-knowledge proofs for circuit evaluation (2009)
Journal Article
Ghadafi, E., Smart, N. P., & Warinschi, B. (2009). Practical zero-knowledge proofs for circuit evaluation. Lecture Notes in Artificial Intelligence, 5921 LNCS, 469-494. https://doi.org/10.1007/978-3-642-10868-6_28

Showing that a circuit is satisfiable without revealing information is a key problem in modern cryptography. The related (and more general) problem of showing that a circuit evaluates to a particular value if executed on the input contained in a publ... Read More about Practical zero-knowledge proofs for circuit evaluation.