While working on the URU Card project, I realized just how practical the credit card form factor really is—so I redesigned URU Key into URU Card Pro. It now fits in a wallet, runs on an ultra-thin Li-Ion battery, and includes a tiny OLED display for feedback. Same secure guts, much better usability!
Got a fresh batch of URU Card PCBs, and this time I used them to build a full hard shell case—just by stacking boards together. No 3D printing needed! I also switched to a PCB antenna (zero cost!) and prepped the layout for a future USB interface with the FT260 chip. It’s compact, wallet-friendly, and fully functional.
Finally, a working BLE-based FIDO2 authenticator on Arduino! The URU Card project now supports basic credential creation and authentication via ESP32. Still early-stage (with hardcoded keys for now), but it’s enough to pass WebAuthn tests in Windows—and it’s open for everyone to try and build on.
After a lot of requests to open-source URU Key, I’m starting a new project—URU Card! It’s a wallet-sized, open-source FIDO2 authenticator with an OLED screen, touch keyboard, and ESP32 brain. No biometrics (for now), but secure, DIY-friendly, and easy to build with Arduino libraries. Want to join in?
It’s been a while since the last URU Key update, but the project’s still alive and kicking! Chrome dropped BLE support (ouch), but Windows still plays nice. Plus, I got official docs from Fingerprint Cards (🎉), and even tested URU Key with Windows Hello. Oh—and a new open-source project is coming soon!
Hardware is done! After months of prototyping, I finally finished the compact 40×15mm URU Key device—complete with ESP32, fingerprint scanner, security chip, LiPo battery, and USB-C. It’s basically a fitness tracker… but for secure authentication. Now onto the software (and maybe a proper case 😅).
It’s official—URU Key is now a real, standalone device! I added the custom power board, used spring-loaded pins for easy firmware updates, and screwed everything together into a compact 35×20×10mm unit. Hardware’s basically done—now it’s time to dive deeper into the firmware, especially the biometric side.
After getting FIDO2 working on Android, I gave it a go on the ESP32. Started with Arduino, but switched to ESP-IDF for more control. It’s super stripped-down—only one in-memory credential and a button for user presence—but it works! Got both registration and login running. Video inside!
Spent a couple weekends deep-diving into a real FIDO2/WebAuthn implementation—and wow, it’s more complex than it looks. Ended up rebuilding the BLE GATT server on Android for better control. Got “Make Credential” working (video inside!), plus found a quirky Chrome spec mismatch along the way.