PDFTron Validation fails once two or more signature are added

Product: PDFNetPython3
Product Version: 9.1.0

I’m currently working on a project that requires me to be able to add 2 or more signatures to a PDF file. However, once more than one signature is added, PDFTron signature verification would fail.

I asked the question on stack overflow. Ryan reached out to me and suggested me to discuss it here. I hope I can get a reply from support team soon. Thanks :slight_smile:

Hello, I’m Ron, an automated tech support bot :robot:

While you wait for one of our customer support representatives to get back to you, please check out some of these documentation pages:


Thank you for reaching out. As discussed on Stackoverflow, Adobe is not strictly following the PDF standard when it comes to signature validation, which in the past has left it open to some attacks and spoofs.

This is why we have the e_compatibility_and_archiving option to allow some relaxation of validation, rather than the preferred/safer e_maximum option.


To assist you further it would be great to learn more about your requirements.

Especially with regards to Validation and if there are particular vendors you are targeting.

1 Like

Dear @Ryan, thank you for reaching out to me. I’ve been very busy with the project lately. Basically, it requires me to add multiple digital signatures to a PDF file indicating multiple people has approved the document. I’m also using self-signed certificate for each signature. Can you tell me if there’s a way I can add multiple signatures without causing a verification failure? I really hope there is a solution to this issue.