ZCash is a decentralized and open-source cryptocurrency that offers privacy and selective transparency of transactions. ZCash payments are published on a public blockchain, but the sender, recipient, and amount of a transaction remain private. ZCash is based on peer-reviewed cryptographic research, and built by a security-specialized engineering team on an open source platform based on Bitcoin Core's battle-tested codebase. Our improvement over Bitcoin is the addition of privacy. ZCash uses advanced cryptographic techniques, namely zero-knowledge proofs, to guarantee the validity of transactions without revealing additional information about them.