Privacy Comes to the OP Stack
Privacy Boost by Sunnyside Labs is the first privacy offering by an Optimism core developer. A privacy SDK that integrates directly into any OP Stack chain, bringing confidential computing to Sunnyside customers. Encrypted token transfers, private smart contract logic, compliance-compatible architecture. Live on OP Mainnet today for Sunnyside customers, with priority integration support for OP Enterprise clients.
The Privacy Wall
Every institutional player evaluating blockchain infrastructure hits the same wall.
"We can't put our customers' transaction data on a public ledger."
This isn't a hypothetical objection. A large payment provider processing billions in volume told us directly: they wanted to move operations on-chain, but the moment their compliance team looked at public chain architecture, the conversation stopped. Transaction amounts visible to anyone with a block explorer. Counterparty relationships exposed. Competitive positions readable in real time. Enterprises can't put treasury movements and trading strategies on a ledger competitors and front-runners can read. Consumer-facing apps can't ship products where user balances and transaction history are public. And regulators are increasingly mandating that blockchain applications protect users' financial information on-chain.
At DAS earlier this month, privacy was named the single one of the most important barrier to institutional on-chain adoption. The same message came through from every direction: institutions won't move on-chain without protecting competitive data. When we surveyed the OP community about what matters most for scaling on-chain payments, built-in privacy ranked number one at 30.4%. Above faster finality. Above lower fees. Above better UX.
The demand was clear. The question was who would build it.
Sunnyside Labs
Sunnyside Labs has been building core OP Stack infrastructure for over three years alongside OP Labs and other core developers. Sequencer performance, benchmarking, core infrastructure development. They know this stack at the protocol level.
The cryptographic foundation caught up to their ambition. Zero-knowledge proofs got fast enough for production workloads. Trusted execution environments got secure enough for institutional requirements. The primitives needed to add privacy without sacrificing performance crossed a threshold that didn't exist eighteen months ago.
Sunnyside built on that foundation. Privacy Boost is the result: confidential computing custom-built for the OP Stack, by engineers who helped build the stack it runs on.
What Privacy Boost Does
Until now, enterprises have been forced into a false choice: expose all data transparently on a public chain, or go opaque with privacy solutions that create new problems.
Privacy Boost brings configurable privacy to the OP Stack at the application layer. It plugs directly into the infrastructure enterprises are already using.
Everything the OP Stack already offers stays intact: Ethereum security guarantees, access to a broad ecosystem of 50-plus chains, open-source protocol evolution from a global contributor base, developer tooling and talent, shared infrastructure economics.
What Privacy Boost adds:
Confidential token transfers. Send and receive tokens without exposing balances or transaction amounts on-chain. The privacy model uses a UTXO architecture, which provides stronger guarantees than account-based approaches by naturally breaking the link between transactions.
Private smart contract logic. Run computations on encrypted data. Applications can process sensitive information without revealing it to validators or other network participants.
Compliance-compatible architecture. Auditable access with programmable policy. TRM Labs integrated for sanctions screening. Sunnyside designed a full-trace audit view for MiCA (EU) and BSA (US) requirements. Privacy doesn't mean opacity. Compliance teams can audit what they need to audit. The goal is protecting customer data from public exposure, not from authorized oversight.
Drop-in SDK. No migration required. No new chain. No new tooling. Sunnyside customers can add Privacy Boost to any existing OP Stack chain without rebuilding anything. SDKs available for TypeScript, React, iOS, Android, and Rust.
How It Works
Privacy Boost uses a ZK plus TEE hybrid architecture. This is a deliberate design choice.
Zero-knowledge proofs handle correctness and confidentiality. Every private transaction is mathematically verified without revealing the underlying data. ZK guarantees that the computation is correct and that sensitive information stays encrypted.
Trusted execution environments operated by Sunnyside handle integration simplicity and scale. TEEs provide strong guarantees that even Sunnyside cannot see customer transaction data while enabling sub-500 millisecond proof generation and high throughput via proof aggregation. Sunnyside runs, manages, and scales the ZK prover infrastructure so customers don't have to manage that complexity. TEEs also enable the regulatory-friendly audit features that make Privacy Boost deployable in regulated environments.
Most privacy implementations force a choice: security or performance. ZK-only approaches are mathematically elegant but slow at scale. TEE-only approaches are fast but rely entirely on hardware trust assumptions. The hybrid takes the strongest property of each. ZK for correctness and confidentiality, TEE for throughput, simple integration, and regulatory compliance.
Privacy Boost has completed a security audit by OpenZeppelin, with the full report available at docs.privacyboost.io/audit.
The system also includes a forced withdrawal mechanism. Users can always exit via a mechanism similar to the OP Stack's native withdrawal path, regardless of what Privacy Boost operators do. Self-custody guaranteed at the protocol level.
The Complete Picture
The OP Stack handles scaling. 3.6 billion transactions in late 2025, over 61% of Ethereum L2 fee market share, 50-plus chains in production. OP Enterprise handles managed operations: hosting, sequencer management, security monitoring, compliance customizations, SLAs.
Privacy was the missing piece. Every enterprise prospect pointed to it. Sunnyside built it. Custom for the OP Stack.
Scaling. Managed services. And now, privacy.
"As we work with banks, fintechs, and institutional partners looking to move on-chain, privacy consistently comes up as a non-negotiable requirement. Privacy Boost checked every box: performance, regulatory readiness, seamless integration, and self-custody. That's why we're excited chose to work with Sunnyside is launching theon the first privacy offering for the OP Stack."
Jing Wang, CEO + Co-Founder, OP Labs
"The technology was mature enough. The demand was there. Building it natively on the OP Stack was the right path because that's the infrastructure we know and the team that knows us."
Taem Park, CEO + Co-Founder, Sunnyside Labs
What's Next
Privacy Boost is live on OP Mainnet for Sunnyside customers. Enterprise deployment documentation and integration guides are available at privacyboost.io. OP Enterprise clients get priority integration support - contact the OP Enterprise team to discuss integration, or visit privacyboost.io for technical documentation.
This is the first of many privacy solutions on the OP Stack. The ecosystem is built to support the broadest range of enterprise requirements. Sunnyside just proved it.