Digital Signature

What is a Digital Signature in PDFs

A digital signature in PDFs serves as a way to verify the authenticity and integrity of a document.

It is a cryptographic mechanism that ensures that a PDF file has not been tampered with since its creation and that it originates from the expected sender. Digital signatures use public-key cryptography, where the signer generates a unique digital certificate containing their public key. This certificate is used to encrypt a hash value of the document, which is then embedded within the PDF.

Recipients can verify the signature by decrypting the embedded hash value using the signer's public key, ensuring that the document has not been altered and comes from the expected source.

Digital signatures provide assurance in the authenticity, integrity, and non-repudiation of PDF documents, making them crucial for sensitive or legally binding files.

There are many software applications and online services available that support digital signature functionality for PDF documents.