Onchain privacy has felt harder to use than it should
The need is obvious: people, companies, and institutions need ways to use crypto without exposing every balance, transfer, position, and interaction by default. But in practice, privacy has usually meant accepting trade-offs across assets, wallets, applications, liquidity, and user experience.
That is not how privacy becomes useful at scale
For privacy to matter in onchain finance, it has to work inside the environment people already use. It needs to support existing assets, applications, and liquidity, while still making sense for builders, institutions, and businesses that need confidentiality without giving up accountability.
That is what STRK20 brings to Starknet
STRK20 introduces a privacy framework for all ERC-20 assets on Starknet. It brings privacy into Starknet’s assets, wallets, and applications, allowing supported assets to move through private flows and applications to offer privacy directly to users.
That changes what crypto privacy can be: not an alternative environment for users willing to leave DeFi behind, but a native capability to an existing ecosystem that can add enhanced capabilities to improve the products, assets, and financial flows already being built on Starknet.
Privacy Starts in Your Wallet
This is the first phase of STRK20 live today on Starknet:
- Privacy begins in the wallet: Accessed through Ready X and Xverse.
- Shield the asset: Inside the wallet, users select the asset they want to shield. This is a one-click, near instantaneous action.
- Shielded Assets: Once shielded, a public balance becomes a private balance hidden from public view, controlled by the same wallet.
- Use private swaps: Once shielded, users can access private swaps using the same wallet, with routing across liquidity in the Starknet ecosystem.
- Use private transfers: Users can also make private transfers to others inside the privacy pools.
- Unshield when needed: Move assets back from a private balance to a public balance with a simple one-click flow. No waiting or hidden charge. This is a one-click action.
How STRK20 Works
STRK20 uses a note-based privacy pool on Starknet. When an ERC-20 asset is shielded, it is deposited into the STRK20 privacy pool and represented as an encrypted note. Private actions spend existing notes and create new ones, allowing activity to be verified without exposing the full transaction details.
Each private transfer is validated by a zero-knowledge proof. The proof confirms that the notes being spent exist, belong to the spender, have not already been spent, and that input and output values balance. Starknet verifies the proof onchain before the pool state is updated.
Public observers can see encrypted notes and required protocol metadata. For private transfers, they do not see the sender, receiver, amount, or which private balances were used.
STRK20 is built for Starknet’s proving environment. Proofs are generated with Stwo, while Cairo is used across the proof logic and contract code. Encrypted notes are stored directly in Starknet contract storage. This matters because privacy systems depend on the soundness of the proving stack. StarkWare has spent years investing in the reliability and formal verification of core Cairo and STARK infrastructure, giving STRK20 a strong technical foundation to build on.
STRK20 also supports multiple token types in a single pool, avoids scanning the entire pool for note discovery, and removes the need for a separate note-commitment tree by storing encrypted notes directly onchain.
Together, these design choices give STRK20 private transfers, double-spend protection, efficient note discovery, multi-asset support, Starknet DeFi integration, and a path toward private onchain activity with defined disclosure when required.
For further reading: Technical Paper linked here
Disclosure, When Required
STRK20 is built for privacy without removing accountability.
By default, private transfers do not reveal the sender, receiver, amount, or notes being spent. But STRK20 also includes an encrypted viewing key framework that gives a path to disclose specific transaction information when required.
This allows a third party auditing entity to trace specific information (such as a user’s transaction history) in response to a legitimate compliance or regulatory request, without exposing uninvolved users or the wider privacy pool.
The result is privacy with defined disclosure: confidential by default, accountable when required.
Why Starknet Takes A Different Approach
STRK20 is designed around a simple principle: privacy should work inside normal onchain activity, not outside it.
Starknet makes this practical through STARK proofs, scalable verification, and Cairo-based execution. Private transactions require proof generation and onchain verification, and Starknet is built to make that computation efficient enough for regular use.
Shielded transactions cost 4 STRK, giving STRK20 a practical cost profile for wallet, payment, trading, and DeFi activity.
That foundation creates benefits across the ecosystem.
- For users, privacy becomes easier to access because it is integrated into familiar wallet flows.
- For builders, privacy becomes easier to adopt because applications can integrate private flows via SDK, without needing to build an entirely separate privacy stack from scratch.
- For institutions, privacy becomes operationally useful because confidentiality can exist alongside a path for disclosure when required.
- For asset issuers, STRK20 gives supported tokens a path to privacy on Starknet without deploying a separate privacy-specific version or fragmenting liquidity.
What STRK20 Enables Across Starknet
STRK20 is a framework that teams across the Starknet ecosystem can build into their own products.
Privacy can now appear across wallets, trading, lending, payments, vaults, games, identity systems, and new financial applications without every team needing to build a separate privacy stack.
It also creates room for products built around privacy from day one, including payroll, donations, treasury flows, private markets, and other forms of confidential onchain activity.
Below are some of the teams bringing these use cases to Starknet.
Wallets and identity
- Ready and Xverse have integrated one-click shielding for assets on Starknet, with native private swapping routed using avnu. Support across both mobile and desktop extensions.
Trading and liquidity
- avnu provides trading routing across all Starknet venues and gasless execution for private asset flows through its Paymaster.
- Ekubo serves as a key liquidity venue where private swaps can settle against existing Starknet markets.
Lending, yield, and vaults
- Vesu will support shielded assets, bringing privacy to lending and borrowing.
- Endur, Starknet’s liquid staking layer, supports private staking flows for shielded tokens such as xstrkBTC and more.
- ForgeYields, a cross-chain yield allocator, is applying privacy to its protocol, enabling private yield farming for DeFi.
- Troves is building automated yield and vault strategies with private deposits and positions.
- Privily is building a privacy neobank and financial appchain, anchored on a STRK20 privacy-enabled stablecoin.
- Zylith is a call auction darkpool that enables private order flow while reducing timing and access-pattern leakage.
Prediction markets
- Polyhedge is building autonomous prediction agents that earn on idle capital, with position and intent kept private.
Gaming
- Provable Games, the team behind Loot Survivor, is exploring the opportunity to use STRK20 for hidden in-game information and private governance.
For more use cases and ideas: 11 Things You Can Build with STRK20
What Comes Next
Today’s launch is the first phase of STRK20 on Starknet: wallet-enabled privacy, shielded balances, and private swaps through supported wallets.
From here, support will expand across the rest of Starknet DeFi. That includes private lending, broader trading interfaces, expanded wallet support, and more applications integrating STRK20 into their core products.
The next phase is developer-facing. Starknet will open-source the wallet API and release SDK infrastructure so builders can add private flows without building a separate privacy stack from scratch.
That next phase will also extend STRK20 beyond Starknet-native users. Applications and users on other EVM chains, Solana and more will be able to access Starknet’s privacy pool as a privacy layer for cross-chain activity, bringing immediate cross-chain capabilities to private flows.
Where To Start
STRK20 is live, and there are several ways to get involved:
- Use privacy on Starknet
- Explore the Privacy Hub
- Visit strk20.starknet.io the privacy hub, with activations, rewards, and ecosystem updates planned.
- Activations will roll out continuously over the coming weeks.
- Visit strk20.starknet.io the privacy hub, with activations, rewards, and ecosystem updates planned.
- Build with STRK20
- Request access to developer tooling, including the wallet API and SDK infrastructure.
- Access the STRK20 website here.
- Apply to the Proof of Privacy Incubator
- Teams with privacy-focused ideas can apply to Proof, the Starknet Foundation-backed incubator.
- Applications will open this week
- Teams with privacy-focused ideas can apply to Proof, the Starknet Foundation-backed incubator.
Privacy where crypto works
On Starknet, it starts with shielding in the wallet. From there, the goal is broader: privacy as a native capability across the assets, applications, and financial flows people already use, giving builders a way to add privacy to existing products or build entirely new privacy-first applications. This is how better applications get built on Starknet.
