Paper 2009/126
Threshold Attribute-Based Signatures and Their Application to Anonymous Credential Systems
Siamak F Shahandashti and Reihaneh Safavi-Naini
Abstract
Inspired by the recent developments in attribute-based encryption, in this paper we propose threshold attribute-based signatures (t-ABS). In a t-ABS, signers are associated with a set of attributes and verification of a signed document against a verification attribute set succeeds if the signer has a threshold number of (at least t) attributes in common with the verification attribute set. A t-ABS scheme enables a signature holder to prove possession of signatures by revealing only the relevant (to the verification attribute set) attributes of the signer, hence providing signer-attribute privacy for the signature holder. We define t-ABS schemes, formalize their security and propose two t-ABS schemes: a basic scheme that is selectively unforgeable and a second one that is existentially unforgeable, both provable in the standard model, assuming hardness of the computational Diffie-Hellman problem. We show that our basic t-ABS scheme can be augmented with two extra protocols that are used for efficiently issuing and verifying t-ABS signatures on committed values. We call the augmented scheme a threshold attribute based c-signature scheme (t-ABCS). We show how a t-ABCS scheme can be used to realize a secure {threshold attribute-based anonymous credential system (t-ABACS) providing signer-attribute privacy. We propose a security model for t-ABACS and give a concrete scheme using t-ABCS scheme. Using the simulation paradigm, we prove that the credential system is secure if the t-ABCS scheme is secure.
Metadata
- Available format(s)
- Category
- Public-key cryptography
- Publication info
- Published elsewhere. An abridged version of this paper is to appear in AfricaCrypt 2009. This is the full version.
- Keywords
- Attribute-Based CryptographyAnonymous Credential SystemsIdentity-based CryptographyUser PrivacyFuzzy Identity-based Signature
- Contact author(s)
- siamax @ gmail com
- History
- 2009-04-02: last of 2 revisions
- 2009-03-20: received
- See all versions
- Short URL
- https://ia.cr/2009/126
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2009/126, author = {Siamak F Shahandashti and Reihaneh Safavi-Naini}, title = {Threshold Attribute-Based Signatures and Their Application to Anonymous Credential Systems}, howpublished = {Cryptology {ePrint} Archive, Paper 2009/126}, year = {2009}, url = {https://eprint.iacr.org/2009/126} }