Ethereum Foundation Backs Universal Signer App for Passport Prime Hardware Wallet

The Ethereum Foundation has funded a Universal Ethereum Signer application for Foundation's Passport Prime hardware device, with the beta now available — provided users are willing to sideload it manually. Bacca, now CEO of ZKnox, built the application under an Ethereum Foundation grant awarded to ZKnox.

The launch extends Ethereum signing capability to a device that until now has been positioned primarily as a Bitcoin hardware wallet, and it does so through an unconventional funding route: the Ethereum Foundation financing a Ledger co-founder to build signing software for a competing hardware platform.

What does the release actually deliver?

The signer is live but in beta, and the immediate practical constraint is distribution. Users must sideload the application onto Passport Prime — installing software directly rather than downloading it from an official store. Herbert said a future app catalog will let trusted groups push updates directly to users, and that catalog is expected to launch in winter 2026.

The model resembles F-Droid on GrapheneOS, where independent developers ship software without waiting on a central gatekeeper. That architecture matters for security posture: it removes a single approval bottleneck but shifts responsibility onto whoever decides which groups count as trusted.

The hardware underneath

Passport Prime retails for $349 and reached general availability in May 2026, following a $6.4 million funding round for Foundation. The device carries a 3.5-inch touchscreen and 50 GB of encrypted storage, and it combines a Bitcoin hardware wallet with FIDO security keys, two-factor authentication and encrypted file storage.

The engine underneath is KeyOS, an open-source microkernel written in Rust. It runs to roughly 9,000 lines — a deliberately small codebase by operating-system standards — and is designed to isolate apps from one another, so a compromised application cannot reach across the device.

Security stakes just went up

In October 2026, Foundation dealt with a phishing campaign that targeted more than 23,000 customer emails. The company confirmed that devices and private keys were not compromised, and funds stored on Passport devices stayed safe.

Adding Ethereum support expands what users can do with Passport Prime. It also expands the attack surface in a specific, operational way: the number of transaction types, contracts and approval screens a user must understand before tapping "sign." Ethereum signing exposes users to arbitrary contract calls and blind-signing risks that simple Bitcoin transactions do not, which places more weight on the device's display logic and the signer's transaction decoding.

What does this change for hardware wallet users?

For holders of Passport Prime, the near-term takeaway is practical. Anyone already holding the device can test the beta signer now if they are comfortable sideloading, while everyone else may prefer to wait for the app catalog expected in winter 2026.

For the broader market, the Ethereum Foundation funding signing software for a competing hardware platform signals an interest in making secure signing available across multiple devices rather than leaving users dependent on a handful of vendors. If that posture holds, hardware wallet differentiation shifts from exclusive asset support toward open signing infrastructure.

The open question is governance. Herbert described a system where trusted groups can send updates directly to users, so how Foundation decides who counts as trusted will shape both the security and the openness of the platform once the catalog arrives in winter 2026.