Lan Nguyen and Tolga Acar
6 March 2011
This paper introduces and formalizes homomorphic proofs, which allow 'adding' proofs and 'adding' their statements to get a new proof of the 'sum' statement. We propose a construction of homomorphic proofs and show one of its applications which is a new accumulator scheme with delegatable non-membership (NM) proofs. We use this accumulator in extending the BCCKLS scheme  to achieve a delegatable anonymous credential with revocation system. Informally, the accumulator's delegatable NM proofs enable user A, without revealing her identity, to delegate to user B the ability to prove that A's identity is not included in a blacklist which could even be updated afterward. Moreover, the delegation should be redelegatable, unlinkable and verifiable. Security of the proposed schemes is provable. We implement a system for Revocation of Anonymous Credentials (RAC) that bases on the proposed accumulator. RAC could provide revocation for several anonymous credential systems.
In Public Key Cryptography (PKC 2011)
Publisher International Association for Cryptologic Research