Zcash is a value transfer protocol forked off the Bitcoin blockchain. Zcash can be used like Bitcoin, with a few added improvements. With “zero cash technology,” Zcash shields both the amount transferred and the senders, making transactions truly anonymous.
Zcash is one of the new kids on the block in the world of “private transactions.”
An interesting note is that Ethereum is in the process of implementing some of Zcash’s technologies to enable transactions on the Ethereum network to be anonymous as well.
Zcash is being developed by the Zerocoin Electric Coin Company. They’ve had some great successes, most notably JP Morgan’s announcement that they would implement Zcash’s privacy technology to Quarum, a technology JP built on Ethereum.
Zcash was recently featured on the Radiolab episode The Ceremony.