Enabling Privacy in IOU Settlement Networks
Primary Investigator:
Aniket Kate
Pedro Moreno-Sanchez, Tim Ruffing, Aniket Kate
Abstract
The decentralized I owe you (IOU) settlement network Ripple is gaining prominence as a fast, low-cost and efficient method for performing same and cross-currency settlement transactions. Similar to crypto-currencies such as Bitcoin, while the ownership of the wallets is implicitly pseudonymous in Ripple, IOU credit links and transaction flows between wallets are publicly available in an online ledger. This leads to privacy issues with the current Ripple network. To overcome these issues, we propose PrivPay, the first provably secure privacy- preserving payment protocol for settlement networks. The distinguishing feature of PrivPay is the obliviousness of transactions, which entails strong privacy guarantees for settlement transactions at the cost of a non-trivial deployment in the current Ripple network. Second, we propose PathShuffle, a protocol to perform several settlement transactions simultaneously so that the sender and the receiver of the individual transactions remain unlinkable. This approach minimizes the communication and computation overhead for the mixing participants and is fully compatible with the currently deployed version of Ripple.