Paper 2021/1036

Lelantus-CLA

Pyrros Chaidos and Vladislav Gelfer

Abstract

This article presents Lelantus-CLA, an adaptation of Lelantus for use with the Mimblewimble protocol and confidential assets. Whereas Mimblewimble achieves a limited amount of privacy by merging transactions that occur in the same block, Lelantus uses a logarithmic-size proof of membership to effectively enable merging across different blocks. At a high level, this allows value to be added to a common pool and then spent privately, but only once. We explain how to adapt this construction to Mimblewimble, while at the same time simplifying the protocol where possible. Confidential assets is a mechanism that allows multiple currencies to co-exist in the same ledger and (optionally) enables transactions to be conducted without disclosing the currency. Finally, we also describe how we can use Bulletproof “coloring” to enable offline payments, thus addressing one of the original shortcomings of Mimblewimble.

Note: Updated references