On paper, a pen signature works because paper is hard to change. Erase a number and the page shows it. Retype a clause and the ink no longer lines up. The protection was never really the signature — it was the physical object it sat on.
Move the same document onto a screen and that protection disappears completely.
What a scanned signature actually is
It is an image file. Once it exists, it can be:
- cropped out of one document and pasted onto another
- resized, rotated, cleaned up, or re-coloured
- copied a thousand times without wearing out
- lifted from any PDF you have ever sent to anyone
That last one is the part people miss. Every time you email a signed PDF, you are handing the other side a clean copy of your signature. Nothing stops them putting it on a page you have never seen.
The three questions ink cannot answer
When a document matters, you need three things settled. Ink settles none of them online.
- Who signed this? An image has no owner. Anyone can produce it.
- Has the page changed since? An image knows nothing about the text around it.
- Was the signer allowed to sign? An image carries no certificate and no date.
A digital signature answers all three, because it is calculated from the file itself and locked with a key that only the signer holds. If you have not read what that means, start there.
Where ink still has a job
None of this makes ink useless. It is the right tool when:
- the document is genuinely on paper, and stays on paper
- both sides are in the room and can see each other sign
- what you need is a record of intent, not proof against tampering
VeriPatra has a whole Sign and Seal feature for exactly this — you can put your signature or a rubber seal on a PDF and send it. What it will never do is report that ink as a cryptographic signature.
If you add ink to a PDF that already carries a digital signature, the file changes and that signature stops validating. Anyone who checks your copy will see "changed after signing". VeriPatra warns you before you do it, and your original stays untouched.
What to ask for instead
When someone sends you something important — an offer letter, a court notice, a property paper — and it carries only a picture of a signature, you are entitled to ask for better:
- ask for the digitally signed original, not a scan or a printout of one
- if they printed and re-scanned it, the signature is gone; ask again
- if they cannot produce one, that is information too
Checking costs you nothing. Drop the PDF into VeriPatra, read the one-sentence verdict, and you will know within seconds whether there is a real signature underneath.
Drop a PDF in and see the eight checks for yourself. No account, nothing kept.