Description from cryptocompare.com
The REN is an open-source decentralized dark pool for trustless cross-chain atomic trading of Ether, ERC20 tokens and Bitcoin. REN is an ERC20 token built on the Ethereum network. Ren is an ecosystem for building, deploying, and running general-purpose, privacy-preserving, applications using zkSNARK and our own newly developed secure multiparty computation protocol. It makes it possible for any kind of application to run in a decentralized, trustless, and fault-tolerant environment similar to blockchains but with the distinguishing feature that all application inputs, outputs, and state, remain a secret even to the participants running the network.