In legal and financial circles, the terms 'electronic signature' and 'digital signature' are often used interchangeably, but technologically they are fundamentally different. While an electronic signature can be a simple drawn image, a digital signature uses Public Key Infrastructure (PKI) to embed mathematical proof of identity and tamper-evidence directly into the PDF byte stream.
#1The Mechanics of Asymmetric Key Cryptography in PDF
When you digitally sign a PDF, a cryptographic hash (typically SHA-256) of the entire document is generated. This hash is like a unique digital fingerprint of every single byte in the file.
The signer's private key encrypts this hash, creating the digital signature. When the recipient opens the document, the PDF viewer uses the signer's public key (stored in an X.509 certificate) to decrypt the hash and compare it to the current document bytes.
If even a single comma or space in the contract was altered after signing, the hashes will not match, and the viewer displays a prominent warning: 'Document has been altered after signing!'
Conclusion
Ensure your high-value commercial agreements carry undeniable cryptographic integrity with MistPDF.
Häufig Gestellte Fragen
What is a Qualified Electronic Signature (QES) under eIDAS?
A QES is a digital signature created using a qualified signature creation device (like a smartcard or HSM) and backed by an accredited trust service provider, offering the legal equivalent of a notarized handwritten signature.
Can I sign documents privately in MistPDF without cloud exposure?
Yes. All vector signature generation and document flattening execute strictly inside your local browser memory.