Revocation for Delegatable Anonymous Credentials
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
 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.