One of them is Zcash and Dash.
Zcash, a decentralized and open-source cryptocurrency launched in the latter part of 2016, looks promising. “If Bitcoin is like http for money, Zcash is https," is how Zcash defines itself. Zcash offers privacy and selective transparency of transactions. Thus, like https, Zcash claims to provide extra security or privacy where all transactions are recorded and published on a blockchain, but details such as the sender, recipient, and amount remain private. Zcash offers its users the choice of ‘shielded’ transactions, which allow for content to be encrypted using advanced cryptographic technique or zero-knowledge proof construction called a zk-SNARK developed by its team. (Related reading, see: What Is Zcash?)
Dash
Dash (originally known as Darkcoin) is a more secretive version of Bitcoin. Dash offers more anonymity as it works on a decentralized mastercode network that makes transactions almost untraceably. Launched in January 2014, Dash experienced an increasing fan following in a short span of time. This cryptocurrency was created and developed by Evan Duffield and can be mined using a CPU or GPU. In March 2015, ‘Darkcoin’ was rebranded to Dash, which stands for Digital Cash and operates under the ticker – DASH. The rebranding didn't change any of its technological features such as Darksend, InstantX. (Related reading, see: Top Alternative