Verify the authenticity of signatures

The SignSpace service provides a user interface for verifying electronic signatures. The service is used by both service users and external parties. With the help of the service, the recipient can make sure that the signed set of documents delivered to him is original and unaltered.

You can also check the signatures of PDF files, for example, by opening the file with the Adobe Acrobat Reader application.

You can find information about the security and legality of SignSpace signatures here.

Checking PDF signatures

You can check the signatures of a PDF file signed in the SignSpace service after 13 April 2023 by opening the file with the Adobe Acrobat Reader application. You can check the signatures of PDF files signed before 13 April 2023 in the verification service provided by the SignSpace service.

NOTE! If the PDF file to be signed is damaged before uploading it to the SignSpace service, its content is locked or the file has already been signed once, due to technical limitations, an electronic stamp cannot be added to it. In these cases the signature page is created as a separate electronically stamped PDF file. The authenticity of these signatures can be checked in the verification service.

Checking signatures in the SignSpace verification service

In the verification service, the integrity of the files uploaded by the user to the service is checked and these are compared to the original data stored in the service.

To verify signatures, you need the original signed file and its signature information. The signature information can be in different formats:

• On the page attached to the end of the PDF document

• In a separate PDF document

The easiest way to make sure you have all the information needed for verification is to click the Download all files with signatures link in the completed signature request.

Keep this zip file for future reference.

When you want to check the signatures, download the contents of this zip file to the page of the verification service at https://site.signspace.com/en/verification.

When you download the contents of the zip file, you will see the result of the verification.

You can also download a single file from the zip file for verification. If the file has not changed a result is shown, which states that the file was signed as part of a package with two documents.

If the file is not in PDF format and therefore does not contain signature information, then you must upload both the original signed file and the related signature certificate. If you do not upload the appropriate signature information for the signed file, the authentication service returns an error message.

If the contents of the files have changed after signing, the authentication service returns an error message.

Note: When the signed file is not in PDF format or an electronic stamp has not been added to the PDF file due to technical limitations, the immutability of these files can be ensured with hash sums calculated from the files. These checks are also included in the provided verification service.