N&O seminar: Samarth Tiwari (CWI)

Everyone is welcome to attend the next N&O seminar with Samarth Tiwari with the title 'Hide & Seek: Privacy-Preserving Rebalancing on Payment Channel Networks'.

Everyone is welcome to attend the next N&O seminar with Samarth Tiwari with the title 'Hide & Seek: Privacy-Preserving Rebalancing on Payment Channel Networks'.

The talk is a preparation for a conference talk, and might therefore not take as long as previous talks.
The talk is based on a paper which will appear in Financial Cryptography 2022 and can be found on on arXiv:2110.08848.

Abstract of the talk of Samarth Tiwari:
Payment channels effectively move the transaction load off-chain thereby successfully addressing the inherent scalability problem most cryptocurrencies face. A major drawback of payment channels is the need to ``top up'' funds on-chain when a channel is depleted. Rebalancing was proposed to alleviate this issue, where parties with depleting channels move their funds along a cycle to replenish their channels off-chain. Protocols for rebalancing so far either introduce local solutions or compromise privacy.
In this work, we present an opt-in rebalancing protocol that is both private and globally optimal, meaning our protocol maximizes the total amount of rebalanced funds. We study rebalancing from the framework of linear programming. To obtain full privacy guarantees, we leverage multi-party computation in solving the linear program, which is executed by selected participants to maintain efficiency. Finally, we efficiently decompose the rebalancing solution into incentive-compatible cycles which conserve user balances when executed atomically.
Paper: arXiv:2110.08848.