Starknet Launches strkBTC, a Privacy-Enabled Bitcoin Wrapper Built on STRK20

Starknet launched strkBTC on Tuesday, a bitcoin-backed asset that gives holders optional privacy on the Ethereum Layer 2 network. It is the first asset built on STRK20, the new privacy framework that shipped with Starknet’s Shinobi upgrade on April 21.

The token is backed 1:1 by BTC locked on the Bitcoin base layer and redeemable at any time. STRK20 lets users toggle between a public mode, which behaves like any other ERC20 on Starknet, and a shielded mode, which hides balances and transfer amounts using zero-knowledge proofs. Users can move between the two states from within their wallet, with Xverse and Ready among the first wallets to support the asset.

This story is an excerpt from the Unchained Daily newsletter.

When a user shields strkBTC, their viewing key is shared with an independent third-party auditor that can grant scoped access to a single user’s activity in response to a lawful regulatory request, without compromising the broader network’s privacy. StarkWare describes the design as “confidentiality on by default, compliance available when required.”

StarkWare CEO and Zcash co-founder Eli Ben-Sasson called it “private digital cash, the way it should be.” StarkWare has also published a quantum-safe Bitcoin scheme that requires no protocol changes, part of a broader strategy to turn bitcoin into a productive asset on Starknet.

The launch lands against a backdrop of rising privacy demand.

Blockchain security firm CertiK recorded 34 verified physical attack incidents globally in 2026 through early May, a 41% increase from the same period in 2025, with AI tools reportedly aiding attackers to link wallet addresses to real-world identities. The strkBTC roadmap includes integration with BitVM to reduce trust assumptions through a 1-of-N security model, and a longer-term goal of a fully trustless bridge enabled by a potential OP_CAT soft fork.