Startale taps Privacy Boost to bring self-custodial privacy to Sony-backed Soneium app

Startale Group is integrating Sunnyside Labs’ Privacy Boost directly into its Sony-backed Soneium super app, giving users fast, self-custodial shielding and zk-powered private payments without sacrificing auditability or everyday UX.

Startale Group has named Privacy Boost as the official privacy partner for the Startale App, in a move that brings self-custodial, onchain privacy features directly into a consumer gateway to Soneium, the Sony-affiliated blockchain.

Startale App adds native, opt-in onchain privacy

Under the partnership, Privacy Boost will deploy natively on Soneium and integrate into the Startale App, giving users the option to shield assets, send private transfers, and route payments through privacy-preserving flows while retaining control of their keys.

The integration is positioned as a milestone in the Startale App’s evolution into a full consumer front door for the Soneium ecosystem, which is being co-developed by Sony Block Solutions Labs. It also marks the first time Privacy Boost’s technology is embedded in a consumer-facing application, shifting it from infrastructure tooling into an end-user product surface.

The Startale App is designed to make the onchain economy accessible to mainstream users, offering asset management, payments, Mini Apps, and ecosystem reward features in a single interface.
As usage scales, Startale and Sunnyside Labs are explicitly targeting the visibility problem of public blockchains, where balances, transfer sizes, and counterparties are exposed by default.

ZK + TEE stack targets consumer speed and compliance

Privacy Boost brings a hybrid architecture that combines zero-knowledge proofs with trusted execution environments, aiming to deliver private transactions at consumer-grade speed and scale.
The system targets sub-500 millisecond proof generation and throughput exceeding 1,800 transactions per second, while keeping assets in user-controlled wallets and supporting selective auditability for compliance and regulatory checks.

“Not every transaction needs to be private, but every user should have the choice,” said Sota Watanabe, CEO of Startale Group. “With Privacy Boost integrated into the Startale App, privacy becomes something users can enable when it matters. It puts control in their hands to decide when and how they protect their onchain activity. That is what a true SuperApp should deliver.”

As part of the rollout, Privacy Boost will deploy its full protocol stack on Soneium, including smart contracts and TEE infrastructure, making private transfers a native building block for developers on the network. Inside the Startale App, the integration will run via SDK, enabling shielding assets into private pools, private transfers that hide balances and counterparties, and privacy-preserving payment flows intended to support future crypto card functionality.

“Startale is serious about bringing privacy to consumer crypto, from everyday payments and card spending to mini apps,” said Taem Park, co-founder and CEO of Sunnyside Labs. “These are exactly the use cases Privacy Boost was built for, high-performance privacy at consumer scale, with an SDK designed for native application and mini app integration alike.”

The companies say the integration is architected to scale alongside the Startale App’s expansion into new payment flows, Mini Apps, and broader ecosystem integrations, embedding privacy as a default consideration across user interactions rather than an afterthought. For Startale, it fits into a broader mission of “bringing the world on-chain” through Astar Network, Soneium, and consumer products like the Startale App, while Sunnyside Labs positions Privacy Boost as enterprise-grade, self-custodial privacy infrastructure aligned with public-chain principles.