Zcash is a digital currency and an anonymous blockchain. Zcash originated as Zerocoin, a code fork of Bitcoin, in 2014, whose whitepaper was written by Eli Ben-Sasson, Alessandro Chiesa, Christina Garman, Matthew Green, Ian Miers, Eran Tromer, and Madars Virza. The Zcash blockchain was launched in 2016 in an attempt to recreate Bitcoin but with improved user security and anonymity. Zcash offers immensely enhanced privacy in comparison to other cryptocurrencies.
Zcash utilizes zero-knowledge proofs which provide the privacy and security mentioned above. Zcash is one of the first platforms to rely on a specific kind of zero-knowledge proof, zk-SNARKs ( "zero-knowledge succinct non-interactive arguments of knowledge"). Zk-SNARKs allow one party to confirm that it possesses particular information without actually disclosing it, allowing the information to be validated. Zk-snarks are applied to validate “shielded” transactions. Shielded transactions are those that include at least one shielded address and encrypt sender, amount, and recipient data.
In 2021, Zcash released a mainnet for its major network update, NU5. NU5 integrated Halo 2 zero-knowledge proving system (“Halo”), moving Zcash to the Halo proving system. Halo Arc ensures the security of shielded transactions and includes auto-migration, moving funds to the newest shielded pool.