Starknet Launches strkBTC with Optional ZK Privacy

On May 12 Starknet launched strkBTC, a wrapped Bitcoin token on its layer-2 network that can hide balances and transfer amounts through an optional ‘shielded mode’. The token is issued as STRK20 and is compatible with ERC-20 standards.

Users move Bitcoin to Starknet by bridging through partners such as Atomiq and Garden and receive strkBTC in return. When holders enable shielded mode, the chain conceals transaction details and account balances.

Shielded mode uses STARK zero-knowledge proofs. Network validators verify those proofs to confirm a transfer is valid without seeing the sender, receiver or amount. STARK proofs do not require a trusted setup ceremony.

Privacy is optional; users can enable or disable shielded mode. Starknet said the design avoids reliance on a small group of actors for initial key generation.

To support compliance, strkBTC supports viewing keys that holders can provide to auditors to reveal specific accounts. The protocol also includes a blocking layer intended to prevent tokens tied to sanctioned addresses from entering the shielded pool. Starknet described the approach as ‘practical privacy’.

Wallets Xverse and Ready X offer native private transfer features for strkBTC. Bridges Atomiq and Garden provide on-ramps to convert Bitcoin into the wrapped token and bring it into Starknet’s DeFi ecosystem.

Existing wrapped Bitcoin tokens include WBTC, tBTC and cbBTC across multiple chains. strkBTC adds optional native zero-knowledge privacy at the protocol level to that market.

Starknet has positioned itself as an Ethereum scaling solution competing with other rollups on throughput and cost. The network built strkBTC to let users choose confidential transfers while preserving tools for audits and sanctions screening.