Spectrecoin is a privacy-focused cryptocurrency with a Proof-of-Stake (PoS) consensus mechanism. Spectrecoin uses ring signatures, stealth addresses, and Tor to provide privacy and anonymity.

Horizen, formerly called ZenCash, is a cryptocurrency focused on privacy. Horizen has an end-to-end-encryption system with zero-knowledge technology, that allows for anonymous transactions and messaging.
The company suffered a 51% attack in June, 2018 and has since re-branded as Horizen. Horizen hopes to combine anonymous transactions and messaging with an emphasis on community governance.

Boolberry is a Proof-of-Work privacy coin designed to enable completely anonymous financial transactions. Boolberry's architecture reduces block size to improve transactions times, and has a mining algorithm that is ASIC resistant.