Short answer: a digital signature is data stored inside the PDF file and calculated from that file's exact contents. A photo, screenshot or scan is a brand-new file made of pixels. The signature data does not come with it, so there is nothing left to check. VeriPatra will say Could not be verified, with the reason "Photos and screenshots cannot carry a digital signature". Ask the sender for the original PDF file instead.
What it means
When a PDF is signed, the signature is attached to the file, along with a certificate saying who owns the signing key. Checking it means recalculating the file's fingerprint and comparing it with the one that was locked at signing.
A picture of the page has none of that. It may show a green tick, a "signature valid" badge or a signature box, but those are just pixels now. Anyone can copy them, or draw them.
The same applies when:
- a signed PDF is printed and the printout is scanned;
- a signed PDF is turned into an image, or "printed" to a new PDF;
- someone sends a screenshot of the document "to save time".
Each of these produces a new file that was never signed.
What to ask for instead
1. The original PDF, sent as a file
Ask the sender to share the PDF itself, as a document or attachment, not as a photo. On WhatsApp, that means sending it as a document rather than as an image.
2. Or download it from the source yourself
If the document comes from an official portal or an online account, download the PDF from there yourself. You then know it is the issuer's file.
3. Then check it
Open the PDF in VeriPatra, or check it on this website. On a phone, you can share the PDF straight into the VeriPatra app.
When a picture is all you have
Some documents carry a QR code that is itself digitally signed, such as the Aadhaar Secure QR. The VeriPatra app can check some of these codes on the device. Get the app for camera QR scanning.
Otherwise, confirm the document with whoever issued it, using contact details you found yourself.
Common questions
Why does VeriPatra accept images at all?
So it can tell you plainly that a picture carries no signature, instead of leaving you guessing, and so it can look for a verifiable QR code.
I scanned my own signed certificate to keep a copy. Is that a problem?
Keep the scan if it is useful, but keep the original PDF too. Only the original can be verified.
Does "could not be verified" mean the photo shows something untrue?
No. It means the photo cannot prove anything either way. The original PDF might verify perfectly. See the three verdicts.
Related reading: Fake job offer letters and Changed after signing.
Drop a PDF in and see the eight checks for yourself. No account; the PDF is not retained.