Bitcoin is the most sovereign money ever created. It is also the least private money people have ever used. For fifteen years, that contradiction was a feature, not a bug. The same transparency that made Bitcoin trustworthy was the cost of running a financial system anyone could verify.

The world has changed since 2008. The personal and institutional costs of total visibility keep going up, and the existing options for Bitcoin privacy all trade one problem for another.

Universal visibility was always one of Bitcoin’s strengths. It is also one of its constraints. There are use cases that need confidentiality without losing the verifiability that makes Bitcoin worth holding in the first place. That is what STRK20 is for.

STRK20 is a novel privacy framework built by StarkWare. It brings shielded balances and private transfers to Starknet at the protocol level, accessed at the wallet level, without compromising verifiability.

strkBTC is the first asset built on STRK20. It is live today.

Introducing strkBTC

strkBTC is an ERC20 on Starknet, backed by BTC locked on Bitcoin. It is the first asset built on STRK20. STRK20 gives strkBTC two modes: public and shielded.

  • Public mode behaves like any other ERC20. Hold it, transfer it, supply it to DeFi, use it as collateral across Starknet applications.
  • Shielded mode hides selected balances and transfers from public view. Use Shielding from inside your wallet, transact privately, and unshield back to a public balance in one click.

The result is optional privacy, at your discretion, per asset, accessed from the wallet you use on Starknet. 

Privacy with compliant disclosure

Privacy is contextual. The line that matters is not between secret and exposed. It is between privacy that can meet real-world requirements and privacy that cannot. That is contextual integrity, and it is the model strkBTC follows.

When you shield strkBTC, your viewing key is shared with an independent third-party auditor. In the event of a legitimate regulatory request, the auditor may grant scoped access to your activity necessary to respond to the request, without touching anyone else’s privacy. Yes, that means your activity can be unshielded under those conditions. That is the point. A privacy system that cannot interact with the regulated world is an island, cut off from the financial system. STRK20 is built for the opposite: confidentiality on by default, compliance available when required.

Getting strkBTC and how it moves

Privacy features are accessed directly from your wallet, so there are no separate interfaces to learn or products to adopt. Xverse and Ready support strkBTC. Bring BTC into Starknet, hold strkBTC, shield balances, and transfer privately, all from a single wallet interface.

Private transfers also need private transaction fees. If a shielded transfer is private, but the fee payment still reveals the wallet behind it, the privacy model has a leak. avnu provides the paymaster for strkBTC, allowing fees to be handled without exposing the user behind the private action.

To bridge BTC into Starknet, use strkbtc.io (built by StarkWare and powered by Atomiq), atomiq.exchange, or Garden Finance. All three routes lead to the same asset on Starknet. For step-by-step setup, bridging, and Shielding instructions, see the strkBTC launch guide.

For users already on Starknet, avnu supports direct swaps into strkBTC from any supported token.

Every strkBTC is backed by BTC locked on the Bitcoin network. The bridge runs a federated model today, with a roadmap toward a fully trustless architecture. The strkBTC Federation, made up of Twinstake, NEAR Intents, Luganodes, UTXO, and Xverse, operates the infrastructure that moves BTC into and out of Starknet. The Federation post covers the trust model and roadmap in detail.

Put strkBTC to work

strkBTC is designed to be used, not just held. Launch incentives focus where Bitcoin liquidity matters most: Lending markets (Vesu) and Liquidity Pools (Ekubo). Borrow stablecoins against strkBTC collateral. Provide liquidity to core BTC pairs.

Liquid staking is also live on Endur. Users can stake strkBTC and hold xstrkBTC as the liquid representation.

What lands next

strkBTC is the first asset built on STRK20, not the final form of privacy on Starknet.

In the weeks ahead, anonymous swaps on Ekubo and avnu will extend strkBTC from private balances and transfers into private execution, allowing users to swap between supported assets without making the swap public. With anonymous swaps, users will also be able to get xstrkBTC anonymously.

Beyond strkBTC, the broader rollout of STRK20 will bring shielded balances and private transfers to every and any ERC20 asset on Starknet.

The next step for Bitcoin on Starknet

Bitcoin has spent fifteen years building the verifiability that makes it worth holding in the first place. strkBTC brings that asset into private, productive use on Starknet, without compromising what makes it Bitcoin.

Get started at strkbtc.io.