ARPA is a Secure Computation Network Compatible With Blockchains They propose a blockchain-based secure computation network of Multi-party Computation (MPC). ARPA cryptographically enables private smart contract, unprecedented data-at-use privacy protection, as well as scalable computational sharding.
Loki combines a private transaction network based on Monero with economically incentivised service nodes to create a trustless quorum based networking protocol. This protocol allows anyone to route small packets of data in an anonymous and decentralised way. The front end applications that use this packet routing system are private-by-design, and are known as Service Node Apps “SNApps”; the first of which is the Loki Messenger - a decentralised, anonymous and private messaging service. Check out Coinbureau for the complete review of Loki Coin.