Aerendir A-Tag About A-Tag
Proof of human authorship

Made by a Human?

A-Tag is cryptographic proof that a real person signed this file as their own, on their device, at a specific time.

Unforgeable, permanent, anchored to the Polygon blockchain. Stamp your own work to protect your copyright, and verify any A-Tagged file you receive.

Verify a file in your browser Get the app

No app needed to verify. Drop any file, see if it is signed.

Get A-Tag

Sign files from your phone

Install the app on your Android phone. Tap the button below on the phone you want to install on.

A-Tag App

Signs files on your device and anchors the proof to the Polygon blockchain. Also verifies any tagged file you receive.

Download APK for Android Download for iOS (TestFlight)

A-Tag is sideloaded, not from the Play Store. That is why Android will show a warning when you open the APK. That is normal for in-house test builds.

  1. Open this page on the phone you want to install on, and keep the phone in your hand through the whole install.
  2. Tap the Download APK button above. Your browser may ask if you want to keep the file. Tap "Keep" or "Download anyway".
  3. Enable "Install from unknown sources" for your browser if Android asks. This is needed because A-Tag is not (yet) on the Play Store.
  4. Open the downloaded APK to install.
  5. Android may show a warning about the file. Tap "More details" then "Install anyway". When prompted to scan, tap "Scan app". This is a standard Android check for sideloaded apps.
  6. Launch A-Tag to get started.

Questions? info@aermob.com

The flow

How it works

1

Install A-Tag

Download and sideload the APK. Your phone stays with you the whole way through.

2

Sign your files

A-Tag checks that a real human is holding the phone, then stamps the file with your signature, your device, and the exact time.

3

Share and verify

Anyone can verify a tagged file. The proof is anchored to the Polygon blockchain hourly so it cannot be forged.

What is A-Tag

Authorship you can prove

In a world of AI-generated content, A-Tag is cryptographic proof a real human signed a file as their own. A claim that can be shared, and verified by you or any third party.

When you sign a file with the A-Tag app, your device first checks that a real person is holding it. It then stamps the file with your signature, your device, and the exact time. The stamp is permanently anchored to the Polygon blockchain so it can never be forged, moved, or erased.

This permanent, time-stamped claim of authorship is what protects your copyright as creator.