SafeMesh — verified emergency alerts without a mobile network
A HarmonyOS app that passes verified emergency alerts from phone to phone when the mobile network is down — built in 24 hours at HackYeah 2026.
- Award
- 2nd place · Huawei challenge
- Organiser
- HackYeah 2026 · Proidea
- Category
- Hackathons
- Year
- 2026
- Duration
- 24 hours
The challenge
In a crisis the mobile network is often the first thing to fail, and warnings forwarded by hand are easy to alter or fake. Huawei's challenge at HackYeah 2026 asked teams to imagine what's next for HarmonyOS — we picked a problem where getting the right message to the right people, and only the right message, can matter a lot.
What we built
SafeMesh is a native HarmonyOS app that relays signed emergency alerts phone to phone with store-and-forward delivery and acknowledgements. Every device checks the issuer's signature against a pinned key before it shows or forwards an alert, so forged, altered or expired warnings are rejected. An offline map shows the nearest protective points, and the same codebase builds for HarmonyOS and OpenHarmony.
The results
- ↗ 2nd place in the Huawei challenge at HackYeah 2026
- ↗ Forged or altered alerts rejected on every device
- ↗ Working app built in 24 hours on HarmonyOS
Key features
- 01
Phone-to-phone alert relay with store-and-forward
- 02
Signature verification before showing or forwarding
- 03
Offline map of protective points
- 04
Polish and English, dark mode, large text and screen-reader support
Gallery
- ArkTS
- ArkUI
- HarmonyOS
- NearLink Kit
- Crypto Architecture Kit
- Node.js
Let's build your product together
Tell us what you're building — raw notes are fine. In a 30-minute call you'll get honest feedback, a rough timeline and a budget range. No pressure, no sales pitch.
- ✓ Reply within 1 business day
- ✓ NDA on request
- ✓ Free estimate
