Bitcoin Atom (BCA) brings a truly decentralized way of digital asset exchange – with on-chain atomic swaps on board. By using built-in hash time-locked contracts (HTLCs) and its own HTLC API, Bitcoin Atom attempts to disrupt the way we exchange cryptocurrencies today, giving independence from intermediaries and any centralized entities.
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.