Horizen (formerly ZenCash) is an incentive-driven application platform with optional zk-SNARK based privacy features that aims to provide users with control of their digital footprint. Launched in May 2017, without an ICO or pre-mine, the platform enables real-life use cases beyond the ZEN currency, including the ability to privately chat with others, publish information and go anywhere on the web with complete privacy.
The team is working towards releasing the Horizen SDK which will allow developers and enterprises to build an unbounded set of applications, products and services on top of the Horizen technology platform.
In order to accomplish its goals, the project is creating four unique platforms. The first, and main, application of Horizen is the ZEN privacy token, which is designed to be a way to transfer value without revealing individual transaction details.
ZenChat is a security focused messaging application that can function as a standalone app or be embedded in the ZenCash wallet. Messages are stored permanently on the blockchain and rely on specialized “secure nodes” to ensure that communication is not traceable.
ZenPub is currently under development and aims to allow users to anonymously publish data, documents, and other media from shielded addresses using InterPlanetary File System (IPFS).
ZenHide will focus on web traffic privacy. The core concept behind ZenHide is to use a different domain name at various layers of communication.
ZenGrid is an application engineered for rent computation.
InstaZen is built for zero-delay payment processing.
Zen Blockchain Foundation plans to implement several other applications, including a decentralized exchange built on their network (ZenXchange).
Horizen employs an Equihash hashing algorithm, which is a memory-hard, proof of work (PoW) mining protocol. In line with the overall privacy-centric goals of the network Horizen utilizes various cryptographic implementations including zero-knowledge succinct non-interactive arguments of knowledge (zkSNARKs) and shielded addresses, in addition to specialized nodes referred to as super nodes.
zkSNARKs are a cryptographic solution where each party can verify that they have a specific set of information without actually revealing what the information is. For example, in a transaction, one party can verify the value of x without revealing what the value of x is. 1
The use of zkSNARKs also provides the ability to use two types of addresses. The first type is t addresses, which allow for transparent transactions similar to Bitcoin. The second type, z addresses, are referred to as “shielded” addresses because the transactions remain private by hiding the sender and recipient addresses as well as the transaction amount.
Secure nodes operate similar to traditional nodes but have additional security features. Full secure node operators are required to maintain Secure Sockets Layer (SSL) and Transport Layer Security (TLS) certificates. Communication is encrypted from nodes to nodes and clients to nodes. Secure nodes are required to stake ZEN and have the ability to send shielded transactions.
Super nodes are more powerful than secure nodes and as a result have greater staking requirements. Super nodes are tasked with managing critical network and systems functions. After recent updates, Super nodes will be able to bring tracking and payments on-chain or within protocol, as well as the introduction of multi-layer sidechains to enhance the ZenCash system for future services.