Horizen (ZEN) is a privacy-focused blockchain project that originated as a fork of ZClassic, itself a fork of Zcash. It leverages advanced zero-knowledge proof technology, zk-SNARKs, to validate transactions without revealing sensitive details such as the parties involved or transaction amounts, ensuring high privacy and security.

The Horizen ecosystem is built for security and interoperability, featuring the industry’s largest and most decentralized node infrastructure. Its mission is to ensure data integrity and enable real-world applications through its secure, interoperable blockchain ecosystem. Horizen's unique sidechain technology, Zendoo, supports both public and permissioned blockchains, emphasizing scalable data confidentiality.

In addition to its core blockchain functionality, Horizen has developed several privacy-enhancing products for enterprise applications, including ZenChat (a private messaging app), ZenPub (an anonymous publishing platform), and ZenHide (a service providing domain fronting to protect users from censorship and data collection). The ZEN cryptocurrency, which underpins the Horizen ecosystem, was distributed to ZClassic holders at launch, without an initial coin offering (ICO).

ZEN uses the Equihash algorithm for consensus and operates on a Proof-of-Work (PoW) blockchain, with a unique reward distribution model that allocates a portion of block rewards to miners, secure node operators, super node operators, and the Horizen Team Treasury.