Stamp a photo with proof of when it was taken
Capture Cam from Numbers Protocol embeds a C2PA Content Credential and writes a record of the file's fingerprint onchain as you shoot, so later edits can be detected.
- 5 minutes
- 4 steps
- Free app to start; check in the app for any registration credits
- easy
- 1 solution uses it
Editing a single pixel changes a file's fingerprint completely, so tampering shows.
Chapter 1 · The wall
The wall you hit
Real footage gets called fake. A capture stamp lets anyone check it.
Chapter 2 · The power
What changes now
Capture Cam from Numbers Protocol embeds a C2PA Content Credential and writes a record of the file's fingerprint onchain as you shoot, so later edits can be detected.
Chapter 3 · Do it
Do it yourself
- Install Capture Cam on your phone.
- Take the photo or video inside the app.
- Open the asset and copy its provenance link.
- Share the original file and the link together; keep faces and locations safe.
- 5 min
- Free app to start; check in the app for any registration credits
- easy
Wallet or sign-in will not open in here? Open Capture Cam (Numbers Protocol) in a new tab ↗
Chapter 4 · Prove it
Prove it worked
A provenance page shows the capture time and a fingerprint that matches your file.
Chapter 5 · Next star
Your next star
- Publish · 10 min · Files under about 100 KiB are free through ArDrive Turbo; larger ones cost a one-time feePublish a page that stays online without a hostArweave stores data with a one-time payment designed for permanence; ArDrive gives a simple upload app.Go to this star →
- Own · 10 min · The protocol is free; you pay network gas, usually a fraction of a cent on Base and other L2sGive or get a work reference that lives onchainThe Ethereum Attestation Service lets anyone sign a public statement about a wallet, such as 'delivered this project', that anyone can verify later without asking the signer.Go to this star →
Chapter 6 · Build
Build what is missing
A one-tap check where a newsroom drops in a file and sees whether it matches a registered capture.
Who could build it Small newsrooms and fact-checkers.
Real problems
Solutions that use this
Questions
How long does it take to stamp a photo with proof of when it was taken?
About 5 minutes, in 4 steps. The first step is: Install Capture Cam on your phone.
What does it cost?
Free app to start; check in the app for any registration credits. Start with the free parts, and never put in more than you can afford to lose.
Do I need to be technical?
It is rated easy. Capture Cam from Numbers Protocol embeds a C2PA Content Credential and writes a record of the file's fingerprint onchain as you shoot, so later edits can be detected.
How do I know it worked?
A provenance page shows the capture time and a fingerprint that matches your file.
What real problems does this help with?
I need to prove my video is real.