I/O Coin cryptocurrency enables up to 1MB doc AES256 encrypted storage (and transfer), encrypted messaging, private payments and identities. The blockchain is dapps ready via api. It offers up to 15 second POS blocks at 4MB per block.
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.