Paper 2022/288

Spats: user-defined confidential assets for the Spark transaction protocol

Aaron Feickert and Aram Jivanyan


In privacy-preserving transaction protocols, confidential asset designs permit transfer of quantities of distinct asset types in a way that obscures their types and values. Spark is a protocol that provides flexible privacy properties relating to addressing, transaction sources and recipients, and value transfer; however, it does not natively support the use of multiple confidential asset types. Here we describe Spats, a new design for confidential assets compatible with Spark that focuses on efficient and modular implementation. It does so by extending coin value commitments to bind and mask an asset type, and asserting in zero knowledge that this type is maintained throughout transactions. We describe the cryptographic components and changes to the Spark protocol necessary for the design of Spats.

Note: Updates a citation.

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Publication info
Preprint. MINOR revision.
Contact author(s)
aram @ firo org
aaron @ cypherstack com
2022-03-18: revised
2022-03-07: received
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      author = {Aaron Feickert and Aram Jivanyan},
      title = {Spats: user-defined confidential assets for the Spark transaction protocol},
      howpublished = {Cryptology ePrint Archive, Paper 2022/288},
      year = {2022},
      note = {\url{}},
      url = {}
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