Oasis Privacy

Add instant privacy to existing dApps running on any EVM network.

The Oasis Privacy Layer (OPL) is the industry-leading EVM-compatible smart privacy solution that redefines how Web3 developers engineer confidential smart contracts.

What does OPL offer?

Powered by Sapphire, OPL brings the first confidential EVM with interoperable on-chain privacy to Web3.

Customizable Privacy

Different dApps require different levels of privacy. OPL enables privacy on any point of the spectrum, from fully public to completely confidential. Features of a dApp that require privacy can run on Sapphire via OPL while users and assets remain on their host network.


Web3 user safety starts with versatile, cross-chain privacy. The message-passing bridge built into OPL offers easy synchronization between dApp state and the host network using Sapphire’s secure runtime.

Productive Transparency

Forcing all on-chain activity to be completely public can be counterproductive. Instead of relying on basic smart contracts that offer no secrecy, OPL empowers Solidity developers to fine-tune discretionary transparency to the level that best suits their application.

How does OPL work?

How does OPL work?

By integrating OPL, an existing dApp’s contracts, users, and assets can stay on the host network. Elements of the dApp that require privacy can be deployed on Oasis Sapphire. The host network can securely pass messages to and from Sapphire by using OPL’s messaging bridge.

Every blockchain has its own native gas token, which can create cross-chain friction. But, by using OPL, dApps can pay gas with their own native token while still leveraging the confidentiality features of the Sapphire runtime. Messages are passed through and executed on Sapphire. Users can directly interact with confidential contracts. Gas is then paid with whatever token fuels their native network.

Benefits of OPL

EVM Compatible

With full support for the two most popular frameworks, Hardhat and Ethers, you can develop, test, debug, and deploy your dApp using OPL just like you normally do.

Low Complexity

It is much easier to build cross-chain dApps with privacy, speed, and versatility using OPL, in comparison to using zkSNARKs, Fully-Homomorphic Encryption (FHE), or Multi-Party-Computation (MPC).


Oasis Sapphire contracts have access to a range of cryptographic primitives for random number generation, encryption, and asynchronous signatures, with widely adopted algorithms such as Ed25519 and Secp256k1.

How to get started

with OPL

How to

get started

with OPL


Start reading the OPL documentation to build your confidential dApp using OPL.


Join the Oasis community to chat with the engineers behind OPL and other Solidity developers building privacy-first applications with OPL.


Participate in the world of Oasis privacy through an Oasis-organized hackathon.


Apply for an Oasis grant to build privacy-first Web3 dApps on Sapphire or any other blockchain that uses Sapphire or OPL as a privacy layer.

Dive into the code

behind OPL

Explore the public Github repository and start adding it to your projects.

Who uses OPL?

The Oasis Privacy Layer is a privacy platform for all EVM compatible dApps and chains... and we mean it!


Secret voting protects DAO members’ freedom of expression and enables unbiased voting processes. Configurable privacy facilitates better DAO governance.


More on-chain game logic means stronger integrity guarantees and more transparency for Web3 games.


User-controlled data sharing policies and selective disclosure unlock the true potential of on-chain identities.


Private attributes and unlockables add value to collections. They can be used to enable gaming features and to cultivate the relationships between creators and collectors.


Selectively encrypt specific trading parameters to avoid MEV.

And More!

This is only the beginning!

Oasis Privacy Layer FAQ

Is there a tutorial?

The Oasis Docs includes an overview of Oasis Privacy Layer and a full tutorial which walks you through the steps of adapting an application to use OPL for selective privacy where it’s needed.

Is there an example application?

Yes, the ‘Secret Ballot Lite’ application shows how you can vote in private using OPL, where the main contract runs on a Transparent EVM chain such as Binance Smart Chain or Polygon.

Is OPL secure?

The Celer IM bridge is secured by the ‘State Guardian Network’ and has additional dApp safeguards with the Celer IM app guardian. See docs for more.

Sapphire is secured by Trusted Execution Environments (TEE) and the Oasis Layer1 BFT Proof-of-Stake consensus system, see the WhitePaper.

Are bridged messages encrypted?

Messages transmitted via the bridge are not encrypted, however any computation which happens on Sapphire is fully confidential and can operate on secret data.

Which bridge does it use?

OPL uses the Celer Inter-chain Message (Celer IM) Framework. It is very easy-to-use and allows a "plug'n'play" upgrade that often requires no modifications with already deployed code.

Who pays for gas?

Contracts pay for gas on-chain where the message is sent from, this means you can ‘send and forget’ and can expect the contract on the target chain will be called with the message. See Celer IM Overview and the Fee Mechanism pages for more info.

What is Oasis Sapphire?

Sapphire is a confidential EVM with end-to-end encrypted transactions and encrypted storage. This allows contracts to operate on secret data, encrypt and decrypt information, generate random numbers and sign or verify cryptographic signatures.

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