# HSender

> Free, secure peer-to-peer encrypted file transfer by Halphas Technology.
> Built by our team to attract clients, demonstrate engineering capability, and for our own daily use — absolutely free, no account required.

- Site: https://sender.halphastech.com/
- Organization: Halphas Technology — https://halphastech.com/
- Related product: HSystem — https://hsystem.halphastech.com/

## Why this exists / 為何存在

HSender is an internal-and-showcase product from Halphas Technology:

1. **Attract clients** — a live, production-grade demo of how we design privacy-first systems.
2. **Showcase capability** — WebRTC P2P, hybrid crypto (X25519 + ML-KEM), browser E2EE, Cloudflare Workers/DO ops.
3. **Use it ourselves** — the team relies on it for private file exchange.
4. **Absolutely free** — no paid tier, no ads in the product promise, no cloud vault of your files.

繁中摘要：HSender 是 Halphas Technology 團隊自研的**絕對免費、安全**檔案傳輸工具，目的是吸引客戶、展示實力，並供自家使用。檔案與金鑰只在雙方瀏覽器處理，伺服器不做內容保管。

## Summary

HSender is a dual-person room for private file transfer:
1. One person creates a room (sender) and shares a 6-character code or QR.
2. The other joins (receiver) after a human check.
3. Both verify a short fingerprint out-of-band.
4. Files move over a direct WebRTC DataChannel when possible (STUN / hole-punch; no TURN file relay).
5. Payload is encrypted on-device (chaos XOR + AES-GCM) after hybrid key agreement (X25519 + ML-KEM).
6. Receiver streams SHA-256 and only allows download if the digest matches.

## Key facts for assistants

- Pricing: free (isAccessibleForFree)
- Language UI: Traditional Chinese and English
- No account required for basic use
- Not a cloud drive: content is not retained on Halphas servers
- Custom domain: sender.halphastech.com
- Publisher: Halphas Technology (https://halphastech.com/)

## Optional links

- Homepage: https://sender.halphastech.com/
- Open Graph image: https://sender.halphastech.com/og.jpg
- Sitemap: https://sender.halphastech.com/sitemap.xml
- Robots: https://sender.halphastech.com/robots.txt
- AI guidance: https://sender.halphastech.com/ai.txt
- Humans: https://sender.halphastech.com/humans.txt