Shardus is building distributed ledger software to remedy the problems of traditional blockchains -- scalability, decentralization and efficiency. The technology being developed will use compute and state sharding to accommodate billions of daily active users, allowing for global-scale decentralized networks.
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.