Hush

Hush is a cryptocurrency launched on November 21, 2016. It is described as a fork of the Zcash 1.0.9 codebase and as its own blockchain network. The description states it implements zkSNARK using an upstream Zcash 1.0.13 build, plus TLS for secure nodes, TOR nodes, and bitcore. Transactions are described as being sent and received via a secure messaging function that can act as a medium of exchange and a store of value.

The project includes HushList, described as a customized secure protocol and private messenger with a contact list supporting infinite receivers. Receivers are required to use zaddrs, and senders can opt to use taddr pseudonymous addresses. Messages, called HushList memos, are stored in the blockchain encrypted so that only the receiver's private key can decrypt them, with optional text and binary documents attached. The description also says transactions can be shielded or made transparent, and that Hush hides metadata and interoperates with forks.