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Flashpaper

Self-destructing secret sharing with no database

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Hi everyone! This is my first HN and I’m very new to the scene. My name is Min from Bangkok.At first, I just want to create a dead man's switch for personal use and for fun. then, I think about information that self destruct like a spy movie. after that, I try to come up with the better version of Privnote or Bitwarden with self-destruct and some kind of censoring or blocking download ability. Somehow, end up with this product. :OFlashpaper is for sending any information that would be burned after reading (with counting down timer like Mission Impossible movie ! or after 24 hrs max if not opened) Encryption happens in browser and because the key stays after # in the link; server never sees the key (Zero-knowledge for web use) and— because I’m a newbie. I don’t want to connect to database because I don’t have the money and I want things light and simple. So, that’s why Flashpaper keeps things in RAM-only, no database.For AI Agent side, Flashpaper provides a REST API and an MCP server so agents can create secret links easily in dead-drop style that can be claimed only once. The second claim would get a 404 which means someone already took it. However, for the agent API flow, the server sees the plaintext for a moment before encrypting, so this flow is not zero-knowledge like the web flow.Overall, I think it work quite well for web use, but for agent API use, I am not sure this is enough security. All the limitations are listed in SECURITY.md. Some feedback would be appreciated. I make it open source with MIT license, with honorware policy for Enterprise use, like self-hosted docker.Here is my repo https://github.com/mmmpym/flashpaper and you can try it here https://flashpaper.appAgain ! Please feel free to tell me what I missed.Min

HN · launched Jul 28, 2026 · 25 upvotes (top 24%) · 0 views

Niche: encryption and cryptography tools · 147 launches, 21 in the last 7 days ▲ +40% · Explore this niche →

Category and tags

  • Security
  • B2C
  • Not AI
  • Hobby / open-source project

Visit website ↗ Source listing ↗

Could you build this?

Yes Client-side AES-GCM encryption with hash-fragment keys and an in-memory or Redis ephemeral store with auto-expiry is a standard security toy app well within vibe-coding scope.

Discussion

12 comments analyzed.

Competitors mentioned: PrivateBin, Slack internal tool, qntm (secure messaging for agents)

Concerns raised: Sends password in plaintext, not true secret sharing, Rolling custom crypto without proper research, Vulnerable to malicious server actors and browser extensions, No denial of service security model tested, Security theater rather than genuine security

Feature requests: Point-to-point design for agents to eliminate server hosting, Larger text sizes and improved visual hierarchy, Range slider for expiration time settings, Reduce number of buttons and demo text options

Competitors

Other products that read as similar to this one : 101 launches clear the similarity bar, closest 8 shown.

Attention rank: #28 of 102 (itself plus its competitors, highest first, normalized so YC and Product Hunt are compared fairly).

Launched 248 days after the earliest competitor.

The niche, labels, vibe code rating and competitor comparison on this page are analysis by Nicheloom. If you use them, please credit nicheloom.com. How you may use our data.