Chapter

Public Key Cryptography – PKC 2011

Volume 6571 of the series Lecture Notes in Computer Science pp 423-440

Revocation for Delegatable Anonymous Credentials

  • Tolga AcarAffiliated withMicrosoft Research
  • , Lan NguyenAffiliated withMicrosoft Research

Abstract

This paper introduces and formalizes homomorphic proofs that allow ‘adding’ proofs and proof statements to get a new proof of the ‘sum’ statement. Additionally, we introduce a construction of homomorphic proofs, and show an accumulator scheme with delegatable non-membership proofs (ADNMP) as one of its applications with provable security. Finally, the proposed accumulator method extends the BCCKLS scheme [1] to create a new provably secure revocable delegatable anonymous credential (RDAC) system. Intuitively, the new accumulator’s delegatable non-membership (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 that can later be updated. The delegation is redelegatable, unlinkable, and verifiable.