  In this paper, we present a protocol for facilitating trust-less cross-chain
cryptocurrency transfers that preserve privacy of bridge withdrawals. We
leverage zero-knowledge primitives that are commonly used to design
cryptocurrency mixing protocols to provide similar functionality but across two
or more blockchains. To that end, we receive cryptocurrency mixing for free
through the bridge operations and de-scribe how to extend these protocols to
incentivise bridge transfers using past ideas. We describe how resulting
protocols lead to similar vampire style attacks coined in the Uniswap vs.
Sushiswap saga but across chains.
