Credo is the token you earn when someone you don’t know sends you an unsolicited email. You can use the Credo you earn to send your own emails to people you don’t know, trade it for other currencies, or hold onto it as its power increases.
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.