Paper 2022/1286

ZEBRA: Anonymous Credentials with Practical On-chain Verification and Applications to KYC in DeFi

Deevashwer Rathee, University of California, Berkeley
Guru Vamsi Policharla, University of California, Berkeley
Tiancheng Xie, University of California, Berkeley
Ryan Cottone, University of California, Berkeley
Dawn Song, University of California, Berkeley

ZEBRA is an Anonymous Credential (AC) scheme, supporting auditability and revocation, that provides practical on-chain verification for the first time. It realizes efficient access control on permissionless blockchains while achieving both privacy and accountability. In all prior solutions, users either pay exorbitant fees or lose privacy since authorities granting access can map users to their wallets. Hence, ZEBRA is the first to enable DeFi platforms to remain compliant with imminent regulations without compromising user privacy. We evaluate ZEBRA and show that it reduces the gas cost incurred on the Ethereum Virtual Machine (EVM) by 11.8x when compared to Coconut [NDSS 2019], the state-of-the-art AC scheme for blockchains. This translates to a reduction in transaction fees from 94 USD to 8 USD on Ethereum in August 2022. However, 8 USD is still high for most applications, and ZEBRA further drives down credential verification costs through batched verification. For a batch of 512 layer-1 and layer-2 wallets, the gas cost is reduced by 35x and 641x on EVM, and the transaction fee is reduced to just 0.23 USD and 0.0126 USD on Ethereum, respectively. For perspective, these costs are comparable to the minimum transaction costs on Ethereum.

Available format(s)
Cryptographic protocols
Publication info
anonymous credentials blockchain zero-knowledge proofs decentralized-finance (DeFi) know-your-customer (KYC)
Contact author(s)
deevashwer @ berkeley edu
guruvamsip @ berkeley edu
tianc x @ berkeley edu
rcottone @ berkeley edu
dawnsong @ berkeley edu
2022-09-30: revised
2022-09-28: received
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Creative Commons Attribution


      author = {Deevashwer Rathee and Guru Vamsi Policharla and Tiancheng Xie and Ryan Cottone and Dawn Song},
      title = {ZEBRA: Anonymous Credentials with Practical On-chain Verification and Applications to KYC in DeFi},
      howpublished = {Cryptology ePrint Archive, Paper 2022/1286},
      year = {2022},
      note = {\url{}},
      url = {}
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