DigitalNote is developing a privacy focused blockchain whose transactions will be resistant to analysis. The network will have a hybrid Proof-of-Work (PoW) and Proof-of-Stake (PoS) consensus mechanism and will be powered by the native XDN coin.

Hush is a cryptocurrency and messaging protocol that is focused on privacy. It uses a the equihash mining algorithm, which is a Proof-of-Work (PoW) consensus mechanism. It offers a high degree of privacy, and allows users to transact and send messages anonymously.
Hush is a fork of Zcash, and uses zk-SNARKS for zero-knowledge cryptography. Hush will allow developers to deploy Ethereum smart contracts on the Hush network.
The founders of Hush are closely associated with Komodo.

ZCash is a privacy focused cryptocurrency protocol that enables users to make transactions anonymously. Users to hide the sender, receiver, and amount of every transaction. ZCash has several high profile advisers and investors, including: Roger Ver, Gavin Andresen, and Vitalik Buterin.
ZCash has a fixed supply of 21 million coins; 20% of which will be allocated as a founders reward that is split between investors and developers. This founders reward has been the subject of controversy and has led to a fork of the ZCash protocol.