Digital Signature

In recent years most companies switched to different methods of electronic document management. This allows to drastically shorten time for business clearance, simplifies document accounting and archiving. But electronic document management also rises the issue of documents authenticity and validation.

Digital signature is an effective way to protect document from changes and identify true sender.

Digital signature ensures that signed document wasn’t changed by anyone other than its author. It is most common way to authenticate document content. PDF signature has digital certificate, provided by trusted certificate center.

Master PDF Editor allows to validate digital signatures, create them and sign documents.

Creating Signature and Signing

Document must be signed after its editing is over. If the document was changed after signing, these changes might corrupt the signature.

To create a signature, you must have a digital certificate and perform following actions:

  • Choose Forms > Signature in Main menu or click edit-sign Signature button on the toolbar. In a document, choose a rectangle where digital signature must be located.
  • Choose Tools >Hand Tool in Main menu or press hand Hand Tool (Alt+4) button on the toolbar. To create a signature left click a signature form. (If Edit Document edit-select or Edit Forms edit-formis selected, left click twice) When Signature Properties window has popped up, choose required certificate in Sign As field.

P.SIn Mac and Windows certificate must be previously copied to system certificate storage. In Linux you have to open certificate file (as a rule, it has .p12 extension) and enter private key password.

  • Press Sign button.

In macOS and Windows you’ll have to permit the application to access certificate storage. When signing, you’ll be prompted for file name and location. Choose file name to sign and save PDF document.


Digital Signature Validation

Master PDF Editor can be used to validate signatures in PDF files. If Edit Document edit-select or Edit Forms edit-formtool is on, double click certificate or click it once if Hand Tool handis on. You’ll see a window with certificate validation result.

Signature is VALID

Signature is valid, document wasn’t changed after signing and certificate was provided by trusted certification center.

Signature is INVALID

Issues occurred when validating the signature. Document was changed or damaged after signing.

Signature validity is UNKNOWN

Signature is valid, document wasn’t changed after signing, but certificate isn’t trusted.

To make certificate trusted:

For Windows and Mac OS X: You must add certificate’s open key to system certificate storage.

For Linux: Press Information button, view certificate properties and then press Add to Trusted Identities button.