Radium is a Proof-of-Stake cryptocurrency that serves as the base blockchain for SmartChain Core which expands the utility of Radium far beyond that of a standard coin, with features such as identity-address linkage, proof-of-existence, file checksum verification and validation, and decentralized elections and voting. All of these features exist in a 100% distributed data-layer within the Radium 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.