Blockchain-verified ownership

Prove you made
it first
permanently.

AI is trained on creative work without permission. Cairn gives you a permanent, shareable timestamp that proves you made it first — before anyone else could claim it.

No crypto wallet needed
Files never leave your device
Permanent proof
Cairn
Ownership verified
brand_identity_final.ai
Anchored February 21, 2026
This is a permanent, tamper-proof record that this file was owned and anchored on-chain by a verified Cairn user. It cannot be altered or deleted.
cairn.app/proof/0x4f2a8c3d1e9b6f5a7c4d2e8b3f1a9c6d
Recorded on Base
Share your proof
How it works

Three steps to permanent proof

01

Drop any file

Drag a document, image, design, or piece of writing into the Cairn extension. Your file never leaves your device.

02

Anchor it on-chain

Cairn creates a cryptographic fingerprint of your file and writes it permanently to the Base blockchain with a timestamp.

03

Share your proof

Get a permanent link anyone can open — cairn.app/proof/... — that shows your verified ownership record. Forever.

Pricing
Starter
$5
20 anchors
$0.25 per anchor
Recommended
Standard
$12
75 anchors
$0.16 per anchor
Pro
$25
200 anchors
$0.13 per anchor
Permanent on-chain timestamp for each file
Shareable proof page for every anchor
Files never leave your device
Credits never expire
Get started — add to Chrome
No credit card required to install · Credits never expire