On August 8, 2025, in Riga, Latvia, Sazmining CEO & Co-Founder Kent Halliburton joined two developers he had just met — Oren and Julius — for his first-ever hackathon. The challenge? Build a working Bitcoin-related solution in just two hours during the high-energy Bitcoin++ Hackathon.
The trio walked away with third place and a functional prototype called NoteGuardian — a tool designed to make Nostr note signing on desktop significantly more secure.
The Problem: Desktop Signing Risks
If you use multiple Nostr clients in your browser, your NSEC (private key) can be scattered across tabs, leaving you exposed. While mobile apps are generally more secure and self-contained, desktop environments can be hostile to sensitive key storage. Existing solutions like “nsec bunkers” offer protection but can be slow and overly complicated.
The Solution: NoteGuardian
NoteGuardian moves your NSEC out of your desktop entirely and stores it securely on your phone. From there, it wirelessly connects to your desktop over a local Wi-Fi connection (no internet), allowing you to encrypt, decrypt, and sign events without exposing your private key to the browser environment.
Here’s how it works:
- Step 1: Pair your phone and desktop by scanning a QR code.
- Step 2: When your desktop needs to sign a Nostr event, the request goes to your phone.
- Step 3: You review the JSON, approve or deny the request, and the action completes securely from your phone.
If the phone is removed from the environment, the desktop can no longer sign events — instantly cutting off access and improving security.
What the Team Built in Two Hours
Because of time constraints, the team implemented NoteGuardian as a website prototype rather than a full mobile app. Even so, it demonstrated seamless pairing and signing over local Wi-Fi. Future improvements could include:
- Converting it into a dedicated mobile app
- Adding Bluetooth connectivity
- Enhanced storage-at-rest protections on the phone
Despite competing feedback from attendees on whether it should remain a website or become an app, one thing was clear: the idea filled a real need.
Kent’s Leadership Under Pressure
In a hackathon setting, quick decision-making and focus are everything. While Oren and Julius handled the coding, Kent kept the team aligned, clarified priorities, and ensured the project met the challenge brief. These same skills are what drive Sazmining’s growth — guiding complex projects from concept to delivery under tight deadlines.
Why This Matters for Bitcoin and Sazmining
Events like Bitcoin++ foster the kind of rapid innovation that pushes the Bitcoin ecosystem forward. At Sazmining, we share that same spirit — solving tough problems, improving security, and making Bitcoin participation accessible to more people.
Kent’s success at Bitcoin++ is a great example of the leadership and problem-solving mindset we bring to everything we do, from mining operations to empowering Bitcoiners worldwide.
Discover how Bitcoin innovation happens in real time — explore Sazmining’s mission and start mining your own wild sats today.