Launched in 2016 by Zooko Wilcox-O’Hearn and based on the Zerocoin protocol, Zcash (ZEC) is a decentralized and open-source privacy-focused cryptocurrency that enables selective transparency of transactions. Zcash transactions can either be transparent or shielded through a zero-knowledge proof called zk-SNARKs. This allows the network to maintain a secure ledger of balances without disclosing the parties or amounts involved. Instead of publishing spend-authority and transaction values, the transaction metadata is encrypted and zk-SNARKs are used to prove that nobody is being dishonest.