The End of Walled Gardens: Foundation Launches Open Ethereum Signer

BOSTON, Nov. 12, 2026 -- For years, the hardware security industry has operated on a paternalistic model: trust the manufacturer, stay within their walled garden, and wait for them to approve the tools you need to secure your digital life. Today, that paradigm shifts toward user sovereignty. Foundation, a hardware security firm known for its open-source ethos, announced the beta launch of the Universal Ethereum Signer on its Passport Prime device. But the real story isn't just the application itself—it is the underlying system that allows it to exist, fundamentally challenging how we think about digital ownership and corporate control.

Developed by Ledger co-founder Nicolas Bacca—now CEO of the cryptography venture ZKnox—and funded by an Ethereum Foundation grant, the app runs on KeyOS, Foundation's open-source operating system. It allows users to review and sign Ethereum transactions on dedicated, air-gapped hardware, keeping their private keys completely isolated from internet-connected phones or computers. Crucially, it bypasses traditional industry gatekeepers, allowing developers to build and deploy directly to users.

Breaking the Walled Garden

In the business of digital security, control is often disguised as safety. Legacy hardware wallet manufacturers have historically functioned much like Apple's App Store, maintaining strict oversight over what software can run on their devices. While this closed-ecosystem approach mitigates certain risks, it also creates a bottleneck. Users are entirely dependent on the manufacturer's internal roadmap, business priorities, and willingness to support new networks or features.

Foundation’s KeyOS, initiated in late 2022, dismantles this structure. It operates as a permissionless platform where independent developers can write software, design user interfaces, and release updates without requiring Foundation’s explicit approval. Passport owners can then install these applications themselves, transforming their hardware from a static product into a dynamic, evolving tool.

"When you buy security hardware, you should be able to keep using it as your needs change," said Zach Herbert, cofounder and CEO of Foundation. "You shouldn't have to buy another device every time you want a new capability or wait for the manufacturer to build it. We built KeyOS so developers can bring those ideas to users themselves."

This approach democratizes security infrastructure. It acknowledges that the systems allowing communities to thrive must be adaptable and open to collective innovation, rather than siloed within a single corporate entity.

An Unlikely Alliance for Universal Security

The development of the Universal Ethereum Signer brings together an unexpected coalition of industry heavyweights. Nicolas Bacca spent years architecting the closed-source secure elements that define Ledger's product line. Now, heading ZKnox, he is building a flagship application for a competitor’s open-source platform.

This transition underscores a growing industry consensus: the future of secure computing requires transparency. "Having enough memory lets us reuse well-tested open source code instead of writing everything from scratch," Bacca explained regarding the development process. "On Passport, we can do that in an open development environment, with KeyOS keeping the signer separate from other apps on the device."

The Ethereum Foundation’s backing of ZKnox further validates this open-source trajectory. By funding an application explicitly designed to be universal—capable of running across multiple hardware platforms rather than being locked to one—the organization is investing in the resilience of the entire ecosystem.

“We're pleased to support ZKnox's work on the Universal Ethereum Signer, an open source app designed to run across multiple hardware platforms,” noted Nicolas Consigny, a member of the Ethereum Foundation’s Strategy Team. “The app launches first on KeyOS, with additional hardware integrations already in development.”

ZKnox’s broader mandate, which includes optimizing post-quantum cryptography to drastically reduce transaction costs on the Ethereum network, signals that this signer is merely the groundwork for a much larger, quantum-resistant security architecture.

The Architecture of Sovereign Computing

The technical backbone making this permissionless ecosystem possible is KeyOS's sandboxed architecture. In traditional embedded systems, granting a third-party application access to the device often meant risking the exposure of all stored data. KeyOS, a microkernel operating system written in Rust, isolates applications from one another.

It provides each app with its own protected environment, dedicated storage, and specific permissions. The Universal Ethereum Signer, for example, generates and manages its own signing keys by default. These keys are cryptographically separated from those used by the device's Bitcoin wallet, login credential manager, or encrypted file storage. This isolation is the critical innovation that allows users to safely consolidate their digital lives onto a single $349 device without creating a single point of failure.

Furthermore, the application maintains the strict air-gapped security model that hardware purists demand. Transactions are prepared on a companion mobile or desktop wallet, then transmitted to the Passport Prime via QR code. The device's camera scans the request, and the user reviews the details on the screen. Once approved, the hardware generates a digital signature, displayed as another QR code, which the companion wallet scans to broadcast the transaction. No USB cables or Bluetooth connections are required, entirely eliminating remote attack vectors.

To combat the rising threat of sophisticated phishing attacks and malicious smart contracts, the app implements Verifiable Signing. In addition to standard transaction parameters like destination, amount, and network fees, the device displays a cryptographic fingerprint of the transaction data. Users can independently verify this fingerprint before authorizing the signature, providing a crucial layer of consumer protection in an often-predatory digital landscape.

Beyond Maximalism to Multi-Asset Reality

For Foundation, the launch of the Universal Ethereum Signer represents a strategic evolution. Founded with a strong focus on Bitcoin-centric tools, the company is expanding its purview to accommodate the complex, multi-asset reality of modern digital ownership.

The modern user does not exist in a vacuum. They interact with decentralized finance protocols, manage digital identities, and hold diverse portfolios. By integrating Ethereum support, the hardware manufacturer is acknowledging that digital sovereignty cannot be limited to a single network. It must encompass the entire spectrum of a user's digital footprint.

This launch follows the introduction of "Legacy Mode," which allowed existing open-source apps developed for Ledger to run on Passport devices. With the Universal Ethereum Signer, users are now experiencing software built natively for KeyOS, optimized for its specific security architecture and user interface.

Currently available as a manual installation via the Ethereum GitHub organization, the application targets developers and early adopters. However, Foundation plans to distribute the app through its upcoming native app catalog this winter, streamlining the installation process for everyday users.

As the boundaries between our physical and digital lives continue to blur, the infrastructure securing our assets and identities becomes increasingly critical. The collaboration between Foundation, ZKnox, and the Ethereum Foundation offers a compelling blueprint for the future: one where security is verifiable, development is permissionless, and control remains firmly in the hands of the individual.