PAdES

What exactly is PAdES format? Digital documents are increasingly being signed electronically. Once they are registered they must be stored correctly – sometimes for several years and in other cases permanently.

¿What is PAdES format?

PAdES stands for PDF Advanced Electronic Signatures. It’s a technical standard to refer to a set of extensions and restrictions used when signing PDF documents electronically.

This standard defines specific profiles to comply with ETSI standards for digital signatures.

By default, the electronic signature is always embedded within the signed PDF document and it is only human-readable. It does not support parallel signing (same document signed by several recipients without following a sequential order) and requires PDF software such as Adobe to sign and verify the electronic signature.

Types of extensions

There are several profiles defined by PAdES (ETSI TS 102 778) to answer different needs and scenarios:

• PAdES Basic. Basic profile that meets the requirements set out in ISO 32000-1.
• PAdES-BES Profile (Enhaced). This profile specifies an advanced PDF signature based on CAdES-BES and incorporates option of including a timestamp (CADES-T).
• EPES Profile (Enhaced). This profile specifies an advanced PDF signature based on CAdES-EPES. It is the PAdES-BES Profile adding a signature policy identifier and optionally a reference to the type of commitment.
• PAdES-LTV Profile (Long Term). It’s the long-lived signature format. This profile allows to extend the validity of signatures in PDF format indefinitely. It can be used together with PAdES-CMS, PAdES-BES or PADES-EPES profiles. This profile is used to ensure validation many years after the completion of the signature. That is, it guarantees long-term validation.

PAdes vs. other formats

The choice between one or the other will depend on the type of document and the desired action to be taken with them after they are electronically signed.

Below you will find other formats supported by our solutions:

• CAdES: (CMS Advanced Electronic Signatures) is a set of signed data extensions with cryptographic message syntax (CMS) making it suitable for advanced electronic signatures. A significant feature of this format is that electronically signed documents can remain valid for long periods of time, even if the underlying cryptographic algorithms break.
• XAdES (XML Advanced Electronic Signatures): A set of extensions to the XML-DSig recommendations in XML file. Suitable for signing financial transactions electronically. Its XML data structure is human-readable and contains all necessary information to identify the signer.

If you are still not sure which electronic signature format you need to speed up your processes, please explain your scenario and we will get in touch with you as soon as possible. 

Viafirma Documents: A comprehensive, simple and secure solution that supports PAdES format

From Viafirma Documents backend, we can configure our signature policies requesting the signer to include some legal evidence (images, OTP verification, etc) when accessing the sign page. Once all the steps are completed, the document will be signed electronically and the legal evidence will be considered attachments to the PDF to increase the legality of the signing process.

To eSign a document remotely, server-based signatures are a must. This will be performed automatically by uploading any valid certificate (either company or manager’s one) to the software. Although in case of not having one, Viafirma’s default signature certificate will be used. Once uploaded, in settings a drop-down menu with the different PAdES extensions will appear, selecting the one that best suits our needs.