Starknet Launches strkBTC, Shielded ERC‑20 Backed by BTC

Starknet launched strkBTC on May 12. The token is an ERC‑20 on Starknet backed by BTC locked on Bitcoin’s base layer. Users can use strkBTC in a public mode that behaves like other wrapped Bitcoin tokens or switch to a shielded mode that hides selected balances and transfers from outside observers.

Under the design, BTC is locked on the Bitcoin base layer and a five‑member federation moves coins between Bitcoin and Starknet. When BTC is moved into Starknet, strkBTC is issued as an ERC‑20 token. Shielded balances are stored on Starknet in encrypted form and verified with in‑protocol proofs. Starknet routes viewing keys to an independent third‑party auditor so regulators or counterparties can be granted access to transaction data when required.

Starknet published a privacy argument on April 10. By April 20, version 0.14.2 was live with native in‑protocol proof verification and support for encrypted balances. On April 28 Starknet confirmed that Atomiq and Garden would route BTC and WBTC liquidity into strkBTC. The five‑member federation was disclosed on May 7, and the product launched on May 12.

Other privacy approaches work on different technical and governance models. Liquid is a sidechain where Confidential Transactions hide amounts and asset types and a federation handles peg operations. WBTC combined with privacy layers such as RAILGUN shields ERC‑20 assets after BTC is converted and passes through custodial bridge infrastructure. Fedimint and Cashu provide private payments through federated mints or Chaumian e‑cash, with users depositing BTC into a mint and receiving private payment claims. Silent Payments and BIP‑352 offer receiver‑level privacy on Bitcoin by mapping a reusable off‑chain address to unique on‑chain addresses for incoming payments without moving BTC off the base layer.

Starknet’s architecture requires trust in the federation that handles peg operations, the bridge routing liquidity, the smart contracts on Starknet, and the third‑party auditor that receives viewing keys. In shielded mode, balances and certain transactions are concealed on‑chain while viewing keys allow selective disclosure when required.

Starknet identifies potential users such as corporate treasuries and OTC desks that need confidential transaction records combined with the ability to provide audit access for compliance purposes.