{"id":17732,"date":"2021-04-29T06:00:00","date_gmt":"2021-04-29T04:00:00","guid":{"rendered":"https:\/\/www.viafirma.com\/blog-xnoccio\/?p=17732"},"modified":"2026-07-24T10:42:25","modified_gmt":"2026-07-24T08:42:25","slug":"pades","status":"publish","type":"post","link":"https:\/\/www.viafirma.com\/en\/pades\/","title":{"rendered":"PAdES"},"content":{"rendered":"\r\n

What exactly does the PAdES format mean? Digital documents are increasingly being signed electronically. And, once registered, they must be stored correctly; sometimes for several years and in other cases permanently.<\/p>\r\n

In this context, the various extensions of the PAdES format allow different types of validity periods to be set<\/strong>. In this article, we will look specifically at what this format and its various extensions entail, how they differ from other options, and how they are used via Viafirma Documents.<\/p>\r\n

What is the PAdES format?<\/h2>\r\n

PAdES stands for PDF Advanced Electronic Signatures.<\/strong> It is a technical standard referring to a set of extensions and restrictions<\/strong> used when electronically signing PDF documents.<\/p>\r\n

This standard specifies precise profiles<\/strong> that make it compatible with ETSI standards for digital signatures.<\/p>\r\n

By default, the electronic signature is always embedded within the signed PDF document<\/strong>, which can only be read by people, unlike other formats. PAdES manages signatures sequentially or incrementally, ensuring that each new signature respects the integrity of the previous ones. It requires PDF software <\/strong>such as Adobe to sign and verify the electronic signature.<\/p>\r\n

Types of PAdES extensions<\/h2>\r\n

Within this signature format, various profiles defined by PAdES (ETSI TS 102 778) have been developed to meet different needs and scenarios:<\/p>\r\n

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  1. PAdES-B-B (Basic):<\/strong> The basic level, which guarantees integrity and complies with the requirements specified in the ISO 32000-1 standard.<\/li>\r\n
  2. PAdES-B-T (Timestamp):<\/strong> Includes a timestamp from an external authority, certifying the exact time of signing.<\/li>\r\n
  3. PAdES-B-LT (Long Term):<\/strong> Long-term signature format. This profile allows the validity of signatures in PDF format to be extended indefinitely. It can be used in conjunction with the PAdES-CMS, PAdES-BES or PAdES-EPES profiles. This profile is used to guarantee validation many years after the signature was created. In other words, it guarantees long-term validity.<\/li>\r\n
  4. PAdES-B-LTA (Archive): <\/strong>The highest level, which applies successive timestamps to protect the document against future advances in computing that could compromise current cryptography.<\/li>\r\n<\/ol>\r\n

    Why choose PAdES over other formats?<\/h2>\r\n

    Unlike other formats, PAdES offers unique advantages:<\/p>\r\n