International Association for Cryptologic Research (IACR)
Abstract
We present two zero knowledge protocols that allow one to assert solvency of a financial organization instantly with high throughput. The
scheme is enabled by the recent breakthrough in lookup argument, i.e., after a pre-processing step, the prover cost can be independent of the lookup
table size for subsequent queries. We extend the cq protocol [EFG22] and
develop an aggregated non-membership proof for zero knowledge sets.
Based on it, we design two instant proof-of-reserve protocols. One is non-
intrusive, which works for crypto-currencies such as BTC where transaction details are public. It has O(n log(n)) prover complexity and O(1)
proof size/verifier complexity, where n is the number of transactions assembled in a cycle. The other works for privacy preserving platforms
where the blockchain has no knowledge of transaction details. By sacrificing non-intrusiveness, the second protocol achieves O(1) complexity for both the prover and verifier
