Starknet brings programmable privacy to Zcash-style assets

Starknet now offers programmable private money, the kind of confidential digital cash Zcash pioneered, through its new privacy features.

The effort runs on two tracks. One is STRK20, a token privacy framework that is live on Starknet, the Ethereum layer 2 network. The other is Ztarknet, a project still in development that would bring Starknet’s execution engine to Zcash as its own layer 2.

What STRK20 actually does

STRK20 is a framework for token-level privacy. It applies to any ERC-20-like asset, the standard format for most tokens in the Ethereum ecosystem.

Once a token uses STRK20, its balances and transfers can be confidential. The sender, the receiver, and the amount can all be hidden from public view.

The framework supports DeFi activity such as swaps, lending, and staking while keeping transaction details private.

Compliance is built in through two mechanisms: viewing keys and selective disclosure. A viewing key lets an authorized party, such as an auditor, see transaction details that remain hidden from everyone else. Selective disclosure allows a user to prove specific facts about their activity to a specific party without exposing everything to the entire network.

The research describes the result as enabling Zcash-like private assets directly on Starknet. The first major asset to use STRK20 is strkBTC, a shielded form of Bitcoin on the network.

The road from testnet to mainnet

By November 2025, the Ztarknet testnet had launched with a live explorer. It demonstrated verification of Circle STARK proofs on a modified Zcash testnet.

Then came Starknet v0.14.2 in April 2026. The upgrade enabled native STARK proof verification through a proposal called SNIP-36, which laid the groundwork for STRK20.

STRK20 itself was activated by June 2026.

Ztarknet remains in development. Its design uses ZEC, Zcash’s native token, to pay settlement fees on the Zcash base layer. It relies on the Madara sequencer, which orders transactions, and the Stwo prover, which generates the STARK proofs. Ztarknet is designed to operate without changing Zcash’s existing shielded pools.

Why the Starknet and Zcash overlap matters

Eli Ben-Sasson and Zooko Wilcox, two prominent figures in blockchain and privacy, are heavily involved in both efforts.

What this means for privacy in crypto

STRK20’s viewing keys and selective disclosure are designed to address compliance concerns that have historically put pressure on privacy coins. The research suggests that as privacy rules tighten globally, platforms offering compliant private transactions are likely to draw institutional interest.

For DeFi, public blockchains broadcast every trade, which exposes users to front-running and makes large positions easy to track. Confidential swaps and lending could make onchain finance more workable for anyone who prefers not to show their hand.

The key milestones ahead sit with Ztarknet. Watch for progress from testnet toward production, how ZEC-based settlement performs in practice, and whether developers actually build on it.