Bitcoin 2 is a scalable Bitcoin fork that supports private transactions through the Zerocoin protocol and nearly instantly verified payments by Masternodes. Bitcoin 2 uses a Proof of Stake system that allows anyone even running a basic laptop to get block rewards while contributing to running the blockchain.
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.