Glossary
Zcash
A Bitcoin fork that adds shielded transactions using zk-SNARKs: addresses and amounts can be fully hidden, with optional transparency for compliance.
Zcash, launched in 2016, was the first widely-deployed cryptocurrency to use zk-SNARKs. It supports two address types: transparent (like Bitcoin) and shielded (where sender, recipient, and amount are hidden under SNARK proofs).
The model gives users a choice: opt into privacy when wanted, transparent when needed. Adoption of shielded addresses has been limited — most volume still moves transparently — but the cryptography has been deeply influential for ZK rollups and other SNARK-based systems.