Field Notes

entity

Zcash

StatusStableUpdatedStands on3 sourcesSupportsnotes

Zcash is a cryptocurrency forked from Bitcoin that adds optional privacy through zero-knowledge proofs. It was the first practical deployment of zk-SNARKs, launched in 2016 by Electric Coin Co.

Addresses and privacy

Zcash has two address types:

  • Transparent addresses (t-addresses), which work like Bitcoin: sender, receiver, and amount are publicly visible on-chain.
  • Shielded addresses (z-addresses), which use zk-SNARKs to encrypt sender, receiver, and amount.

Funds can move between the two types, but each crossing creates a shielding or deshielding boundary that can leak information. A fully shielded (z-to-z) transaction hides all three fields while still proving to the network that the spender owns an unspent note and that no double-spend occurred.

Zcash also supports selective disclosure through view keys, which grant read access to transaction details without spend authority, allowing compliance with audit, tax, or anti-money-laundering rules.

Tradeoffs

The privacy guarantees depend on the shielded pool size. If most transactions use transparent addresses, the shielded pool is small and statistical analysis of shield and deshield boundaries can narrow anonymity. The trusted setup ceremony for the original zk-SNARK parameters is an additional cryptographic assumption that later upgrades have replaced with more distributed ceremonies.

Cryptocurrency design comparison places Zcash’s design beside Bitcoin, Monero, Ethereum, and Solana.

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